Exam 8: Experimental Design

An investigator wanted to see whether packaging information affects the way teenagers rate the effectiveness of soap.The same soap was put in three packages: (a)a pink wrapper that says "For Keeping Your Skin Baby Soft";(b)a red wrapper that says "For Eliminating Acne";and (c)a white wrapper that says nothing.Each teenager was asked to rub his or her face with dirt and wash with soap A;the same procedure was followed for soaps B and then C.The time it took to get the face clean was recorded each time.What is the intended independent variable?

A researcher wants to find out whether gross motor coordination is better in the morning or in the afternoon.To measure coordination,participants balance a book on their heads first in the morning and then in the afternoon.What is confounded with the independent variable?

To control for order effects in a repeated measures design,you should ideally use

A research psychologist has participants serve as their own control group by having them take part in every condition of his study.This experimental approach is an example of a(n)

Which of the following statements is least likely to be correct? A researcher might employ a pretest-posttest design when

Lauren usually receives excellent ratings of her performance on the basketball court.However,her coach rates her performance in today's game much lower than normal because her teammates had an exceptionally good game.What effect may be responsible for today's lower rating?

An investigator wants to see whether packaging information affects the way people rate breakfast cereal.The same cereal is put in three packages: (a)a brown box that says,"To start your day off with a smile";(b)a yellow box that says,"For extra energy all day";and (c)a white box that says,"Fortified with B complex and iron." In this study the

In order to examine environmental factors that influence alcohol consumption,Henry asks the same set of participants to come to the laboratory on several consecutive occasions and fill out a questionnaire before drinking any alcohol.Henry finds that over time,fewer and fewer participants show up to fill out the questionnaire.This lack of continued participant involvement is an example of a _____ problem.

A researcher wants to find out how much fins increase swimming speed.If an independent groups design is used,the researcher would manipulate the variable by

A researcher wants to find out whether campers prefer cotton or nylon sleeping bags.A troop of boy campers tried cotton and a troop of girl campers tried nylon sleeping bags.The sleeping bags were rated for softness and warmth.The confounding variable is

Internal validity means that

Mortality refers to the fact that participants sometimes

A developmental psychologist measures aggressive behaviour in a group of second-grade children before and then again after viewing an aggressive cartoon.This design would best represent a(n)_______ design.

In an experimental design,if awareness of a pretest poses a problem,which of the following would a researcher be least likely do?

A researcher wants to know if a new sports drink improves physical performance.Participants are first measured on the number of sit-ups they can complete in one minute.The participants are then given eight ounces of the new sports drink,and then the number of sit-ups completed in one minute is again measured.The researcher finds that the number of sit-ups completed is less after versus before consuming the new sports drink.This finding is likely a result of a _____ effect.

If a greater percentage of heart surgeons than family doctors are sued for malpractice,can it be concluded that heart surgeons are less competent than family doctors?

Which of the following statements is least likely to be true of using Latin Square?

A researcher wants to examine the effect of room temperature on task performance.She places one group of participants in a room that is 54 degrees,a second group in a room that is 72 degrees,and a third in a room that is 90 degrees.She then measures the amount of time it takes each group to complete an identical task.This design would best represent a(n)_______ design.

Which of the following is NOT a step in the posttest-only design?

In testing the effect of noise on performance of a task,Ernie tests half of the participants in a cool,comfortable,quiet room,and the other half in a hot,noisy room.Ernie's failure to control for temperature of the room may result in a(n)