Everyday Research Methods

Have fun to lose weight

Exercise makes you lose weight, right? Theoretically, yes--exercise burns calories, and that makes the body lose weight. Unless, of course, you eat extra food after exercising...then you won't lose so much.  A series of studies described here shows that when people exert physical activity and think they have exercised, they tend to treat themselves to more calories later. The consequence is, of course, that they find it harder to meet  weight loss goals.

Here's a description of one of the studies:

... the researchers first recruited 56 healthy, adult women, the majority of them overweight. The women were given maps detailing the same one-mile outdoor course and told that they would spend the next half-hour walking there, with lunch to follow.

Half of the women were told that their walk was meant to be exercise, and they were encouraged to view it as such, monitoring their exertion throughout. The other women were told that their 30-minute outing would be a walk purely for pleasure; they would be listening to music through headphones and rating the sound quality, but mostly the researchers wanted them to enjoy themselves.

When the women returned from walking, the researchers asked each to estimate her mileage, mood and calorie expenditure.

Those women who’d been formally exercising reported feeling more fatigued and grumpy than the other women, although the two groups’ estimates of mileage and calories burned were almost identical. More telling, when the women sat down to lunch... the women in the exercise group loaded up on the soda and pudding, consuming significantly more calories from these sweets than the women who’d thought that they were walking for pleasure.

a) The study above is an experiment with several dependent variables. What are the DV's that you see?

b) What is the IV in this study? Is it independent groups or within groups? What design is this--prettest posttest? Posttest only? Repeated measures? Concurrent measures?

c) Sketch a bar graph of the results they describe. Pick one of the DV's for your graph. 

Here's another study conducted in this series:

...the researchers directed a new set of volunteers... to walk the same one-mile loop. Once again, half were told to consider this session as exercise. The others were told that they would be sightseeing and should have fun. The two groups covered the same average distance. But afterward, allowed to fill a plastic bag at will with M&M’s as a thank-you, the volunteers from the exercise group poured in twice as much candy as the other walkers.

d) Is this study correlational or experimental? What are the variables in this study?

 

And here's one more study:

...to examine whether real-world exercisers behave similarly to those in the contrived experiments, the researchers visited the finish line of a marathon relay race, where 231 entrants aged 16 to 67 had just completed laps of five to 10 kilometers. They asked the runners whether they had enjoyed their race experience and offered them the choice of a gooey chocolate bar or healthier cereal bar in consideration of their time and help. In general, those runners who said that their race had been difficult or unsatisfying picked the chocolate; those who said that they had fun gravitated toward the healthier choice.

e) Is this study an experiment or a correlational study? What are the variables in it?

f) What do you think? What's the take-home message from this set of three studies? 

 

Going on an interview? Avoid the "vocal fry..."

You might not know the name "vocal fry," but if you've been on a college campus  lately, you've definitely heard it: Vocal fry is a creaky, low sound that up to 2/3 of college women put at the end of sentences. A friend once called it the "sticky voice." 

The Atlantic just covered a research study on how people perceive others who use vocal fry in a job interview.  The story includes little audio clips of men and women speaking in regular voices and with vocal-fried voices (I recommend listening to them!)

Here's how the study was described: 

Researchers at the University of Miami and Duke University asked seven male and seven female young people to say the phrase “Thank you for considering me for this opportunity” in both a normal tone and in vocal fry. Then, 800 men and women of a variety of ages were invited through an online survey to listen to the samples and [to rate each] speaker (normal or fry) [on how] educated, competent, trustworthy, attractive, and appealing [they were] as a job candidate.

a) This is a factorial design. What are the independent variables?  For each independent variable, indicate if it is independent groups or within groups. Then state the design as precisely as you can.

b) Note that this study has more than one dependent variable. Name at least three dependent variables,

Here's a summary of the results:

For each trait, the listeners preferred the normal voice to the fry voice for both the male and female speakers. They were less likely to say they'd want to hire the person with the fry voice, [and] they found them to be less trustworthy. When making hiring judgments, people preferred a normal voice 86 percent of the time for female speakers and 83 percent of the time for male speakers. Women using fry were viewed more negatively than men doing so, and the negative perceptions were stronger when the listener was also a woman. 

c) Graph the results for the dependent variable, "rated negativity," described in the last sentence above.

d) In the graph that you drew, is there an interaction? (There'd better be!)

e) What about main effects? Based on your inspection of the graph you made, decide whether there will be main effects for the two independent variables in this study. 

 f) given the results and method of the study, did the study design and results allow the journalist to say that "Vocal fry may hurt women's job prospects?"  How might you improve this headline to make it more faithful to the actual study?