Everyday Research Methods

"Fetuses smile for carrots but grimace over kale"

This fetus's facial expression would be judged as more of a cry or grimace. Photo courtesy of FETAP (Fetal Taste Preferences) Study, Fetal and Neonatal Research Lab, Durham University

This fetus's facial expression would be judged as smiling (or lip-pulling). Photo courtesy of FETAP (Fetal Taste Preferences) Study, Fetal and Neonatal Research Lab, Durham University

Even though kale is having a moment as a vegetable (and kale salad is certainly one of my favorites), most folks would agree that carrots taste better than kale.  A new study, covered by multiple news outlets, has demonstrated that even in utero, fetuses agree. They seem to be able to tell the difference between carrots and kale, and they like carrots better!

As you can imagine, this study was a media darling. Here are some excerpts of a report on this study as covered by journalists at CNN. 

The scientists used in-utero facial expressions to infer how babies felt about what their parent had eaten: 

Fetuses create more of a “laughter-face” in the womb when exposed to the flavor of carrots consumed by their mother and create more of a “cry-face” response when exposed to kale [...]

The study looked at the healthy fetuses of 100 women between the ages of 18 and 40 years who were between 32 and 36 weeks pregnant in northeast England.

From this, 35 women were [assigned at random] into an experimental group that consumed an organic kale capsule, 35 were put into a group that took a carrot capsule, and 30 were put into a control group that was not exposed to either flavor.

After a waiting period of 20 minutes post-consumption, the women underwent 4D ultrasound scans, which were compared to 2D images of the fetuses.

Lip corner pulling, suggestive of a smile or laughter, was significantly higher in the carrot group compared to the kale and control group. Whereas ... casting down of the lower lip...– suggestive of a crying face – [was] much more common in the kale group than the other groups.

Questions

1. Using the table below, classify the three main variables mentioned in this study (hint: One variable was manipulated and two were measured)

Variable name (conceptual variable)	How was this variable operationalized?	What are this variable's levels?	Was this a manipulated or measured variable?	Was this an IV or a DV?

2. Was the independent variable manipulated as independent groups or within-groups? 

3. Which of the four basic experimental designs was used: posttest only? pretest-posttest? repeated measures? concurrent measures?  Explain your answer. 

4. Sketch a little bar graph of the results of the "lip pulling" result.

5. Can this study support the causal claim that "eating a carrot pill causes fetuses to make a smiling face"? Apply the three causal criteria. 

6.  The CNN study mentioned the following in their reporting. Which of the four big validities is this addressing? 

Participants were asked not to consume any food or flavored drinks one hour before their scans. The mothers also did not eat or drink anything containing carrot or kale on the day of their scans to make sure it would not influence the results.

7. The 100 fetuses in this study were not a random sample of any population--they were a convenience sample. Why do you think these researchers did not prioritize external validity in this study? Do you think that's a major problem, or not? 

8. Use the Internet to find other media coverage of this study--note any similarities and differences in how the journalists discuss the findings. 

Here's a link to the original empirical article (paywalled). 

Time alone with your thoughts?

Credit: Ground Picture/Shutterstock

Imagine sitting alone with your thoughts for 20 minutes. You wouldn't be allowed to distract yourself with a book, phone, or even walking around. How much do you think you would you enjoy it?  

When this question was asked of participants in a series of studies, most reported that they'd not enjoy time alone very much.  But this study also tested how well their predictions matched their actual experience. The empirical research was published in the Journal of Experimental Psychology: General, and  summarized in a trade magazine for the American Psychological Association. According to the journalist, 

...study lead author Aya Hatano, PhD, of Kyoto University in Japan[, said] “Our research suggests that individuals have difficulty appreciating just how engaging thinking can be. That could explain why people prefer keeping themselves busy with devices and other distractions, rather than taking a moment for reflection and imagination in daily life.”

The research team conducted six studies. Here is an overview of some of them: 

In a series of six experiments with a total of 259 participants, the researchers compared people’s predictions of how much they would enjoy simply sitting and thinking with their actual experience of doing so. In the first experiment, they asked people to predict how much they would enjoy sitting alone with their thoughts for 20 minutes, without being allowed to do anything distracting such as reading, walking around or looking at a smartphone. Afterward, participants reported how much they had enjoyed it.

The researchers found that people enjoyed spending time with their thoughts significantly more than they had predicted. This held true across variations of the experiment in which participants sat in a bare conference room or in a small, dark tented area with no visual stimulation; variations in which the thinking period lasted for three minutes or for 20 minutes; and one variation in which the researchers asked people to report on their enjoyment midway through the task instead of after it was over. In every case, participants enjoyed thinking more than they had expected to.

a) The researchers conducted six different studies. Do these sound like direct replications? Replication-plus-extensions? or Conceptual replications? (you can skip this question if you haven't done Chapter 14 yet)

b) The journalist identifies these as "experiments," so let's assume that each study contains a manipulated variable. Take this study, as described by the journalist:

The researchers found that people enjoyed spending time with their thoughts significantly more than they had predicted [in a variation of] the experiment in which participants sat in a bare conference room or in a small, dark tented area with no visual stimulation. 

In this study, one of the independent variables was "predicted vs. actual".  What is the other main independent variable, or IV? What is the dependent variable, or DV? 

c) Do the same for this study:

variations in which the thinking period lasted for three minutes or for 20 minutes;

In this study, one of the independent variables was "predicted vs. actual". What is the other IV? What is the DV?

d) And for this one: 

In another experiment, the researchers compared one group of participants’ predictions of how much they would enjoy thinking with another group’s predictions of how much they would enjoy checking the news on the internet. Again, the researchers found that people underestimated their enjoyment of thinking. The thinking group expected to enjoy the task significantly less than the news-checking group, but afterward, the two groups reported similar enjoyment levels.

In this study, one of the independent variables was "predicted vs. actual". What is the other IV? What is the DV?

e) Challenge question: For the study above (comparing time alone to looking at news on the internet)  and graph the result. You can compare your graph to Figure 6 in the empirical article (available next to the APA journalist's story, here).

Here's a final caveat about the results. I appreciated this statement because it puts the statistical outcome in concrete and realistic terms: 

It is important to note that participants did not rate thinking as an extremely enjoyable task, but simply as more enjoyable than they thought it would be, according to Murayama. On average, participants’ enjoyment level was around 3 to 4 on a 7-point scale. Future research should delve into which types of thinking are most enjoyable and motivating, according to Murayama. “Not all thinking is intrinsically rewarding, and in fact some people are prone to vicious cycles of negative thinking,” he said.

 

 

Where do you get more creative ideas?

The research tested whether people came up with more, and more creative, ideas when working face-to-face compared to Zoom.
Photo credit: MBI/Alamy Stock Photo

Apparently, researchers have found that Zoom can stifle pairs' creativity. Here's how an empirical study on this topic was introduced by journalists writing for The Guardian:

While the benefits of Zoom and other videoconferencing tools made them indispensable in the pandemic, the research suggests that heavy reliance on the technology comes at a cost to creative thinking.

a) Before moving on, how might you design an experiment to test which type of meeting would be better for creativity? What would your study's independent variable (IV) be? What would the dependent variable (DV) be? 

Let's see how the researchers did it. According to the journalist,  

... the researchers recruited more than 600 volunteers who were paired up to tackle a creativity task either together in the same room, or virtually over Zoom.

The pairs had five minutes to come up with creative uses for a Frisbee or bubble wrap and a minute to select their best idea. Independent judges ruled that turning a Frisbee into a plate was less creative than using it to knock fruit from a tree, while using bubble wrap to send morse code messages was more creative than using it to protect a baby. Overall, those who worked over Zoom had 20% fewer ideas than those who met face to face.

b) In the study above, what was the IV and what were its levels?

c) Was the IV manipulated as between groups or within-groups?

d) What was the DV and what were its possible levels?

e) What simple experiment is this: Posttest-only? Pretest-posttest? Repeated measures? Concurrent measures? 

Now here's a second experiment: 

The same effect was apparent in the real world. In a field study, the researchers analysed ideas for new products generated by 1,490 engineers for a multinational company. The engineers, who were in Finland, Hungary, India, Israel and Portugal, were randomly paired up and given an hour or so to brainstorm products either in person or over Webex videoconferencing. They then selected their best idea.

...the researchers report that the engineers produced more ideas, and more innovative ideas, when working face to face. “They are not only generating a larger number of creative ideas, but their best idea is better,” 

f) This experiment was billed as a "field study." What does that mean? 

g) In the study above, what was the IV and what were its levels?

h) Was the IV manipulated as between groups or within-groups?

i) What were the two DVs in this study?

j) What simple experiment is this: Posttest-only? Pretest-posttest? Repeated measures? Concurrent measures? 

k) The second study is a replication of the first one. What role does replication play in the scientific process? If you've studied Chapter 14, you could identify whether this was a direct replication, a replication-plus-extension, or a conceptual replication.

Interestingly, the journalist notes, "it is unclear whether the impact on creativity holds for larger teams." This statement is a good example of external validity as it applies to situations (rather than the most common focus of external validity, which is on a study's generalizability to participants).

l) What other situations might we wonder about as we consider the external validity of this research? 

The original empirical study was published in Nature. The original study contains a number of interesting additional DVs, including potential mediators for the overall effect on creativity. 

Therapy dogs in the emergency room

The study focused on therapy dogs' effect on perceptions of pain in emergency room patients. Photo: monkeybusiness/Deposit Photos

Adults and children alike can benefit from petting a therapy dog (a friendly pet who makes rounds with a trainer, perhaps to a clinic, pediatric unit, or even on campus during finals week). In this study, covered by journalists at NPR news, researchers from the University of Saskatchewan tested the efficacy of therapy dogs for people who visited an emergency room (ER) complaining of pain. 

 

Here is how the journalist described the study: 

In a controlled trial, researchers asked more than 200 patients to report their pain levels. One group of patients received a 10-minute visit from a therapy dog and the other group did not. After the dog visit, researchers asked patients in both groups to report their pain levels again.

Those who spent 10 minutes with the dog reported less pain [over time], the study found.

Based on this simple description, you can assume that this study was an experiment. 

 

a) What was the independent variable (IV)? What were its levels?

b) Was the IV manipulated as independent groups or within groups? 

c) What was the dependent variable (DV)? 

d) Which of the designs in Chapter 10 does this represent: Posttest only? Pretest-posttest? Repeated measures? or Concurrent measures? 

e) Sketch a small graph of the study's outcome. You don't know what the exact values are, but you should be able to estimate what should be higher and lower. Use either a bar graph or a line graph, following examples in Chapter 10. 

 

The journalist states, "A new study shows that a 10-minute visit from a therapy dog can help relieve patients' pain in the emergency room."  

f) What makes this a causal claim?

b) Assuming that people were randomly assigned to the two groups. Can the study support this causal claim? Name and apply the three causal criteria. 

 

You can read the real study for free: The empirical article is open access in PLOS. 

Swapping saliva

According to the study, even babies know that we don't share our food with just anybody... Photo: szefei/Shutterstock

When you see the photo here, you probably assume the kids are siblings, or at least very close friends. It's not the matching dresses--it's because they're taking turns tasting the same ice cream cone--an activity in which they'll undoubtedly exchange saliva. We humans tend to conclude that people willing to share spit with each other are probably more intimately related. 

Do babies realize the same thing? Apparently so! Here's an NPR story about a research study on whether babies also conclude that people who share saliva  also conclude that they are more closely related. They introduce the story like this: 

"From a really young age, without much experience at all with these things, infants are able to understand not only who is connected but how they are connected," says Ashley Thomas of MIT, who studies what babies and young children understand about the complexities of their social world. "They are able to distinguish between different kinds of cooperative relationships."

As is usually the case, researchers have to get creative to study what young kids think. The present set of studies tested both infants (aged 8-10 months) and young toddlers. They used a puppet show to experimentally manipulate different variables: 

One of their videos shows a woman rolling a ball back and forth with a blue fuzzy puppet. Then another woman shares an orange with that same puppet by putting a slice of orange in her mouth, then letting the puppet nibble on the slice, and then putting it back in her own mouth.

Then they used looking time to measure what infants were thinking:

...the video then shows the two women with the blue fuzzy puppet in between them. The puppet starts to cry and puts its head down, as if it is suddenly unhappy.

When the puppet cried, infants and toddlers looked first and looked longer at the woman who had shared bites of her orange.

"They're looking in that direction because they expect something to happen there," says Thomas. "They expect that woman to be the one to respond to the puppet's distress."

Questions:

a) What is the independent variable (IV) in this experiment? What were its levels? Is it manipulated as independent-groups or within groups? 

b) What is the dependent variable (DV)?

c) Which of the four simple experiments does this seem to be--pretest-posttest? posttest only? concurrent measures? or repeated measures?

d) Sketch a bar graph of the results, putting the IV on the x-axis and the DV on the y-axis. 

Here's another part of the study: 

When the two women were shown with a totally new puppet that started to cry, however, infants and young children looked at both women equally often. This suggested that they didn't see this particular food-sharing woman as especially helpful; instead, her relationship with the puppet was what really mattered.

e) Sketch a bar graph of these results, putting the IV on the x-axis and the DV on the y-axis. 

Like most modern research articles, this one includes multiple studies (three studies, in fact). Additional studies help provide replications of the observed effects, and can also help rule out alternative explanations.  Here is the journalist's description of one of the other studies in the empirical journal article:

To make sure it wasn't just sharing of food that seemed to make babies infer the existence of a close social connection, the researchers created another, similar video. This time, instead of sharing an orange slice, a woman simply put her finger in her own mouth and then put it in a purple puppet's mouth, before putting it back in her own mouth.

Then that same woman also interacted with a green puppet, touching its forehead and then touching her own forehead. After that, the video showed the woman seemingly in distress, with the purple and green puppets looking on.

Infants and toddlers gazed at the purple puppet that had the more intimate, finger-in-the-mouth interaction, as if expecting this puppet to be more affected by the woman's consternation, presumably because they seemed to have a closer relationship.

f) What are the IVs and DVs in this new study?

g) Sketch a bar graph of the results being described.

h) What type of replication is this: a direct replication, a conceptual replication, or a replication-plus-extension? 

i) One possible explanation for the infants' looking behavior in this study is that infants just prefer to look at purple puppets more than green puppets. How could the researchers rule out this alternative explanation? 

Want to read more? here's a link to the empirical journal article, which appeared in the journal Science.

Curbing hate speech with empathy

The study found that empathy-inducing responses like this were more likely to be followed by people deleting their original hateful posts. Photo courtesy of the author

Hate speech abounds on certain corners of social media. Some people post racist, sexist, anti-immigrant, or homophobic comments, and these contribute to a harmful and hateful discourse online. Some companies filter, censor, or censure accounts when they cross the line. Other companies have proved unwilling to ban such content, citing free speech concerns. Recently, some researchers asked if people might engage with such posters online in order to prevent them from posting hate speech. 

The website Optimist Daily ran a story about their work. Here's how they introduced it: 

Led by public policy professor Dominik Hangartner, the research team identified 1,350 English-speaking Twitter users who had posted racist or xenophobic content. The researchers then assigned these users randomly to a control group or one of three test groups. The test groups were then prescribed different counterspeech strategies: empathy-eliciting messages, humor, or warning of consequences.

For example, the empathy eliciting messages might have read "your post is very painful for Jewish people to read...", or "For African-Americans, it really hurts to see people use language like this". Another example can be seen in the comment about immigrants in the photo above, accompanying this post.  

The humorous messages included a meme of an animal with a quip such as "please sir, stop tweeting".

The warning-of-consequences messages read, for example, "Hey, remember that your friends and family can see this tweet too." 

What happened after one of these responses was posted? Here is how the journalist described the results: 

The researchers found that by far, the most effective strategy for getting these users to delete or amend hateful content was counterspeech messages that elicit empathy.

Questions

a) What words in the journalist's story convey that this was an experiment?  I would additionally classify it as a field experiment--can you see why?

b) What was the independent variable? What were its levels? Was the IV manipulated as independent-groups or within groups?

c) There are two dependent variables mentioned in the quotes above. What are they? If you were the researcher, what other DVs would you be interested in? (you can consult the original study to see some of the other DVs)

d) How were the participants in this study selected? Did they use a random sampling method? Or something else? 

e) This study was approved by the researchers' IRB, but the participants in this study apparently did not provide informed consent to participate in the research. Why do you think the IRB approved the study?

Here is a link to the original journal article in PNAS. You can use it to study the graphs of the study's outcome. 

Kids with obesity also need acceptance

The successful intervention for obesity combined lessons about eating and exercise, family dynamics, and peer acceptance. Photo credit: Eviart/Shutterstock

Here's another example of a research summary from The Conversation, which invites researchers to produce  accessibly-written summaries of their own research. 

This one concerns a study that conducted a randomized controlled trial of interventions for kids at-risk for obesity. Here's how the researchers, Amanda Harrist and Laura Hubbs-Tait, described their research:

We conducted a randomized controlled trial in 29 Oklahoma schools. More than 500 first graders who were at-risk for obesity – meaning their BMI was above the 75th percentile – were assigned to either a control group or a group that received a combination of three interventions.

These interventions focused on family lifestyle, family dynamics and the peer group.The family lifestyle intervention focused on healthy food and physical activity. ....

The family dynamics intervention added parenting skills and healthy emotion management. 

The peer group intervention taught social acceptance in the children’s school classrooms, ... teaching children to be more accepting of one another.
(note: please read the post for full details about these three parts of the intervention)

Here are the study's results:

We measured children’s heights and weights at the beginning of first grade and then after the intervention – in first, second, third and fourth grades. Only those children with obesity who received the three interventions – family lifestyle, family dynamics and peer group – had significant decreases in BMI gains compared with the control group.

Questions

a) The authors call this a "randomized controlled trial", so that should tell you they conducted an experiment. What was this study's independent variable (IV) and what were its levels?

b) Was the IV manipulated as independent-groups or within-groups?

c) What was this study's dependent variable? 

d) Which of the four simple experimental designs does this seem to be--posttest only? Pretest-posttest? Concurrent measures? or Repeated measures? Explain your answer. 

e) Sketch a graph of the study's results, labeling your axes mindfully. 

f) In this study, the researchers randomly assigned schools to the different conditions, rather than individual children. Why do you think they might have done it this way? 

 

The researchers' summary in The Conversation focuses on two conditions (control condition and an intervention that combined three elements). But the full study actually contained more than two conditions. You can read the full study here (open access): https://www.mdpi.com/1660-4601/18/16/8744 

 

Increasing vaccination rates in evidence-based ways

One of the evidence-based techniques was to "say because," as these ads illustrate.
Images used with permission from the Government of Jersey

Jersey is a self-governing island in the English Channel off the northwest coast of France. Its population is around 108,000. After the COVID-19 vaccine became widely available, the island's government started campaigns to encourage people to get their shots.  Rather than making up communication strategies that just seemed right, they decided to design strategies based on social psychological evidence.  This article describes the studies they used and how they applied them. Let's take a look. 

Strategy: Say because

One strategy mentioned in the article involves the word "because."

The study:

Ellen Langer demonstrated the persuasive power of the word “because” in her famous studies in the 1970s. People waiting in line to use a photocopier were asked “Excuse me, I have five pages. May I use the copier?” 60 percent agreed. But when the request was accompanied with a reason — “May I use the Xerox machine because I’m in a rush?”—94 percent complied.

[...] even when the word because was followed with a completely meaningless reason — such as “May I use the Xerox machine, because I have to make copies?” just as many people said yes. The study wonderfully demonstrates the motivational influence of the word “because” and its continually reinforced association with the good rationales that typically follow it.

The application:

But just because people pay more attention to the word “because” doesn’t mean that what comes after is less important. Hence our two-step “because-then-reason” strategy. First, we prominently included the word “because” in our vaccination outreach campaigns. Then we followed the word “because” with a personalized reason meaningful to that particular messenger (and their audience).

The images in this post show examples of how the posters highlighted the word because. 

Questions about this strategy:

a)  Before basing an intervention on an empirical study, we'd better be sure that study was experimental (rather than correlational). Why?

b) What were the variables in Langer's study, and what were the levels?  Do you think that Langer's study was experimental or correlational? What are the clues? 

 

Strategy: Build ownership

The study:

A 2020 mega-study conducted by several dozen researchers led by Wharton School professor Katy Milkman demonstrated how a simple change to a text message increased uptake of flu shots. Reminder messages that included the words “your vaccine is reserved for you” boosted rates by as much as 11 percent compared to standard messages such as “protect yourself by getting a flu shot.”

The application:

Milkman’s study provided the inspiration for us to adopt a similar approach in the emails and texts we sent on behalf of the Government of Jersey to citizens whose turn it was to receive their Covid-19 vaccine. The words “your vaccine” were designed to give readers that sense of personal ownership.

c) What were the variables in Milkman's study? What were the levels of each variable?

d) Do you think Milkman's study was experimental or correlational? Explain your answer

e) Why do you think the journalist described this as a "mega-study"? Follow the link to test your hunch. 

f)  The journalist seems to mention only two levels of the independent variable in Milkman's study (the words “your vaccine is reserved for you” versus “protect yourself by getting a flu shot.”). But in the Milkman et al.'s actual study, there were many more levels. Check the link to the study to find out how many other conditions the researchers tested. 

 

Note to Instructors: Figure 1 of Milkman's study shows the effect sizes and CIs for all of the different interventions they tried. It's a really nice way to introduce these statistical concepts. 

 

Evidence-based tips for procrastination

What do the studies suggest about why people procrastinate? Photo credit: Timothy Hodgkinson/Shutterstock

The BBC magazine, Science Focus, collected a set of studies on procrastination that might help students at the beginning of a new school year.  The journalist opens with a couple of simple frequency claims. 

[If you procrastinate,] you’re not alone: an estimated 20 per cent of adults (and above 50 per cent of students) regularly procrastinate.

Then the article addresses three topics: 1. Is procrastination a sign of poor time management? 2. Is procrastination unhealthy? 3. How can we stop? Let's take each topic and apply some research methods content as we go.

1. Is procrastination a sign of poor time management?

The journalist quoted psychologist Fuschia Sirois, who explained that contrary to what many people believe, procrastinators aren't more likely to be bad at time management. Instead, she explains, it's about emotion regulation:

“At its core, procrastination is about not being able to manage your moods and emotions. Although many think impulsivity and self-control are the problems – and they do play a factor – underneath is a poor emotional response.”

As Sirois explains, every person faces stressful situations, demanding tasks that trigger brain activity that involves a brain region known amygdala. And it’s the amygdala that processes emotions and signals threats, capable of prompting a ‘fight or flight’ response linked to procrastination.

“Interestingly, people who say they are chronic procrastinators tend to have larger grey matter volume in the amygdala,” says Sirois.

“This means they will also be more sensitive to the potential negative consequences of their actions, leading to more negative emotions and procrastination.”

a) What were the variables in the amygdala study? Was this study correlational or experimental? 

b) Sketch a scatterplot (or bar graph) of the results Dr. Sirois describes here.

 

2. Is procrastination "bad for your health"?

The journalist implies causality with this headline, and with lines like these: 

...procrastination can cause a lot more problems than missed deadlines. Over decades Sirois has examined the impact of chronic procrastinating on a person’s health, her findings worrying at best – and downright terrifying at worst.

Let's see if the evidence can support these causal claims. He quotes Dr. Sirois again, who stated, 

“People who chronically procrastinate – people who make it a habit – have higher levels of stress and a greater number of acute health problems. They are more likely to have headaches or insomnia or digestive issues. And they’re more susceptible to the flu and colds.”

Even more alarming, Sirois has found that procrastination is a factor that can lead to hypertension and cardiovascular disease, with chronic procrastinators more likely to put off healthy behaviour such as exercise.

c) Is Dr. Sirois describing correlational or experimental evidence here? (Explain your answer by specifying the variables she mentions).

d) Why can't the evidence described by Dr. Sirois support the journalist's assertions about "the impact of chronic procrastinating"? Specify the temporal precedence problem and the internal validity problems here (when you discuss internal validity, specify a particular third, or "C" variable that might correlate with both A and B). 

3. How can we stop procrastinating?

In this section, the journalist describes some intervention studies targeting procrastination.

For example, one compelling Psychological Science paper described how downsizing larger metrics of time (think 48 hours instead of 2 days, or 10,950 days instead of 30 years) can make events seem more immediate, prompting people to engage in upcoming tasks.

You can follow the underlined link in the quoted text (above) to see that this paper described several experiments (for example, the abstract states, "we manipulated time metric".

e) Given the journalist's description (and the empirical study's abstract), name the independent variable in this experiment and name its levels.

f) Name the dependent variable in this experiment.

g) Sketch a bar graph of the study's result, as described by the journalist. 

h). Because this study was an experiment, it is more likely to support causation.
Think about something you have to do in the near future. How can you apply the results from the Lewis and Oyserman study in Psychological Science to that task, to prevent yourself from procrastinating on it? 

 

Selected Answers

a) One variable was "saying you are a chronic procrastinator or not" and the other was "volume of grey matter in the amygdala". Both variables must have been measured, so this was a correlational study.  

b) One axis should have "grey matter volume in amygdala" and the other should have "level of chronic procrastination"; the scatterplot should have a positive slope, but you don't have information on how strong the relationship was, so you can't really know how spread out the dots should be. 

c) This is likely correlational evidence. They are measuring (not manipulating) people's procrastination habits. They are measuring (one cannot manipulate) people's acute health problems, susceptibility to the flu, hypertension, and cardiovascular disease. 

d) We can take acute health problems as an example. Even if there is an association between chronic procrastination (A) and acute health problems (B), we still don't know if the procrastination led to the health problems (A to B), or if the health problems lead to more procrastination (B to A). In addition, there could be some outside variable such as life stressors or poverty (C) that is associated with both procrastination (A) and health problems (B). 

e) The independent variable is apparently "time metric" and the levels were hours vs. days, or perhaps days versus years. 

f) The dependent variable seems to be "how immediate events seem to be"

g) The x-axis should have hours and days, and the y-axis should indicate "how immediate events seem to be". The bar for "hours" should be higher than the bar for "days". 
This study seems to suggest that if you have homework due in two days, you might be more likely to get started on it if you say to yourself, "My homework is due in 48 hours." 

 

Cat-in-the-box

Pancetta the cat sitting in Kanizsa square. Photo and research by Gabriella Smith, M.A.

I've shared several examples of research on pet dogs on this blog, so it's about time I present an example of research on pet cats.

If you own a cat yourself, you've probably noticed that they enjoy climbing into 3-dimensional boxes, baskets, and other containers. You might also know that cats also seem to prefer "climbing" into 2-dimensional boxes--that is, they are likely to sit in a simple square that has been masking-taped onto the floor. A recent study took a closer look at this adorable behavior as part of a test of whether cats are susceptible to a phenomenon known as the Kanisza contour illusion.

As illustrated in the photo of Pancetta that accompanies this post, the Kanisza contour illusion consists of four Pac-Man-like shapes that, when arranged just so, are usually interpreted by humans as a square. Researcher Gabriella Smith wondered if cats, too, would fall for the illusion, so she created an experiment to test it. 

An interesting aspect of Smith's study was that the cats participated in their own homes, an approach called "citizen science." In other words, the researchers  "let volunteers test their own cats at home in a standardized way and then send in the results".

Here's a description of the research study, as covered by NPR's All Things Considered.(The original empirical study was published in a journal published  by Elsevier, which means it's very difficult to obtain, even through universities.):

Participants received booklets with instructions on how to print out and cut up paper shapes that could be taped to the floor to create three options: the Kanizsa illusion, the actual outline of a square, and a control that had the Pac-Man shapes facing outward. The volunteers were instructed to videotape their cats as they encountered these stimuli in short tests over six days, while the volunteers wore sunglasses to avoid inadvertently giving the cats any signals with their eyes.

Their results? That the cats chose to sit in the illusory square as often as they did the actual outline of a square — and more than the non-square arrangement.

Here are some questions about the study.

a) This was an experiment. What was the independent variable (IV) and what were its levels?

b) What was the dependent variable (DV)?

c) Was the IV manipulated as independent-groups or within-groups?

d) Which of the four basic experiments does this study seem to have used--Posttest only? Prettest-posttest? Repeated measures? or Concurrent measures?

e) Sketch a graph of the results that were described (hint--put the three IV groups on the x-axis).

f) In the empirical article, the researchers mention that the presentation of the different IV levels was fully counterbalanced, which means that cats in the study were exposed to multiple trials. Why was counterbalancing necessary, and what might counterbalancing have looked like? 

g) The story mentions that "the volunteers wore sunglasses to avoid inadvertently giving the cats any signals with their eyes.". Which internal validity threat was this designed to prevent?

Now here's a detail about the citizen science aspect of the study:

While hundreds of people signed up for the experiment, in the end the researchers got complete data on only 30 cats..... [Smith] notes the number of people who dropped out of this study and says future efforts along these lines may need to be even shorter and easier to ensure that volunteers are able to complete all the required tasks....This latest study, [in contrast to past work on cats] has the advantage of testing untrained cats in a.... natural setting, 

h) Given this outcome, summarize the pros and cons of the citizen science approach to animal research, perhaps adding some of your own.

i) You might be alarmed that the sample size for this study dropped from hundreds of people to only 30, and you might be tempted to think this study has an attrition threat to internal validity. But attrition isn't an issue for internal validity here--can you explain why?