Exam 10: Introduction to Simple Experiments

What type of experimental design is affected by order effects? What can researchers do to address order effects and how does this fix them?

Dr.Acitelli studies sleep and sleep disorders.She is curious as to whether falling asleep in front of a television set causes people to fall asleep more slowly than falling asleep without watching TV.She recruits a sample of 60 middle-aged women from a local church who reported no history of sleep problems.She creates three conditions.All participants come to the sleep lab for three nights in a row and experience all three conditions.In the first condition (A),participants fall asleep in front of a television that is off.In the second condition (B),participants fall asleep in front of a television that is turned on to the same 24-hour news channel.In the third condition (C),participants fall asleep in front of a television that is turned on to the same 24-hour news channel but is muted.With the use of an electroencephalograph (EEG),the researcher measures how long it takes participants to fall asleep. -Which of the following designs is Dr.Acitelli using?

Experiments use random assignment to avoid which of the following?

Dr.Phillips is a cognitive-developmental psychologist who studies how children learn mathematical principles.His current interest is in studying how children learn multiplication.He recruits 54 second-graders who have not yet learned how to multiply numbers to participate in his study.He is curious as to whether different teaching styles lead to better mastery of the subject.One condition (A)involves having students read a chapter on multiplication from their textbook.One condition (B)involves having students watch a video of cartoon characters explaining multiplication.One condition (C)involves having students being taught multiplication from a teacher.One condition (D)involves having students being taught multiplication by a fourth-grader.In all conditions,participants spend 30 minutes learning the fundamentals of multiplication and are then given the same 15-question multiplication test.The number of questions answered correctly is recorded.The data are below. -Using Dr.Phillips' study as an example,explain the difference between a control group and a comparison group.Why did Dr.Phillips' study not have a control group?

Dr.Acitelli studies sleep and sleep disorders.She is curious as to whether falling asleep in front of a television set causes people to fall asleep more slowly than falling asleep without watching TV.She recruits a sample of 60 middle-aged women from a local church who reported no history of sleep problems.She creates three conditions.All participants come to the sleep lab for three nights in a row and experience all three conditions.In the first condition (A),participants fall asleep in front of a television that is off.In the second condition (B),participants fall asleep in front of a television that is turned on to the same 24-hour news channel.In the third condition (C),participants fall asleep in front of a television that is turned on to the same 24-hour news channel but is muted.With the use of an electroencephalograph (EEG),the researcher measures how long it takes participants to fall asleep. -Given that there are three conditions/levels of the independent variable,how many orders of the conditions are possible in Dr.Acitelli's study?

Define manipulation checks and pilot studies and explain how they address the construct validity of an experiment.

Dr.Acitelli studies sleep and sleep disorders.She is curious as to whether falling asleep in front of a television set causes people to fall asleep more slowly than falling asleep without watching TV.She recruits a sample of 60 middle-aged women from a local church who reported no history of sleep problems.She creates three conditions.All participants come to the sleep lab for three nights in a row and experience all three conditions.In the first condition (A),participants fall asleep in front of a television that is off.In the second condition (B),participants fall asleep in front of a television that is turned on to the same 24-hour news channel.In the third condition (C),participants fall asleep in front of a television that is turned on to the same 24-hour news channel but is muted.With the use of an electroencephalograph (EEG),the researcher measures how long it takes participants to fall asleep. -Given that Dr.Acitelli's participants have agreed to participate for three nights each,which type of counterbalancing should she use?

Dr.Lonsbary is a cognitive psychologist who is curious about how mood affects memory.She recruited 60 high school students and divided them into three groups.Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry,Be Happy").Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again").Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory,Dr.Lonsbary would greet the participant and then ask him or her to draw a card.Participants who drew a 1,2,or 3 were assigned to Group A.Participants who drew a 4,5,or 6,were assigned to Group B.Participants who drew a 7,8,or 9,were assigned to Group C.The participants were then given an unlabeled CD to listen to based on their group assignment.The CD contained either the song selection or five minutes of silence.They were then escorted into a different room,where they were greeted by a research assistant who conducted the experiment.The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen.They were instructed to listen to the CD with headphones while trying to memorize the list of words.All participants were given the same list of 25 words to remember. When five minutes had passed,the screen displayed a question asking them whether they felt happy,sad,or neutral.After the participant responded,a new screen was displayed asking them to type in all the words they could remember from the list of 25 words.All participants were given three minutes to type the words they remembered.Afterward,the participant was thanked and dismissed.In response to the mood question,a majority of Group A participants said they were happy,a majority of Group B participants said they were sad,and a majority of Group C participants said they were neutral in their mood.Dr.Lonsbary found the following results in response to the number of words remembered. -Dr.Lonsbary's study asked participants to report on their mood before completing the memory test.Her decision to include this step was done to address the study's:

Dr.Lonsbary is a cognitive psychologist who is curious about how mood affects memory.She recruited 60 high school students and divided them into three groups.Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry,Be Happy").Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again").Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory,Dr.Lonsbary would greet the participant and then ask him or her to draw a card.Participants who drew a 1,2,or 3 were assigned to Group A.Participants who drew a 4,5,or 6,were assigned to Group B.Participants who drew a 7,8,or 9,were assigned to Group C.The participants were then given an unlabeled CD to listen to based on their group assignment.The CD contained either the song selection or five minutes of silence.They were then escorted into a different room,where they were greeted by a research assistant who conducted the experiment.The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen.They were instructed to listen to the CD with headphones while trying to memorize the list of words.All participants were given the same list of 25 words to remember. When five minutes had passed,the screen displayed a question asking them whether they felt happy,sad,or neutral.After the participant responded,a new screen was displayed asking them to type in all the words they could remember from the list of 25 words.All participants were given three minutes to type the words they remembered.Afterward,the participant was thanked and dismissed.In response to the mood question,a majority of Group A participants said they were happy,a majority of Group B participants said they were sad,and a majority of Group C participants said they were neutral in their mood.Dr.Lonsbary found the following results in response to the number of words remembered. -How many conditions/levels of the independent variable were in Dr.Lonsbary's study?

All of the following are advantages of within-groups designs EXCEPT:

Dr.Phillips is a cognitive-developmental psychologist who studies how children learn mathematical principles.His current interest is in studying how children learn multiplication.He recruits 54 second-graders who have not yet learned how to multiply numbers to participate in his study.He is curious as to whether different teaching styles lead to better mastery of the subject.One condition (A)involves having students read a chapter on multiplication from their textbook.One condition (B)involves having students watch a video of cartoon characters explaining multiplication.One condition (C)involves having students being taught multiplication from a teacher.One condition (D)involves having students being taught multiplication by a fourth-grader.In all conditions,participants spend 30 minutes learning the fundamentals of multiplication and are then given the same 15-question multiplication test.The number of questions answered correctly is recorded.The data are below. -Based on the results of his study,Dr.Phillips hopes to make a causal statement.Explain how his study does or does not meet the three rules of causation.

Dr.Lonsbary is a cognitive psychologist who is curious about how mood affects memory.She recruited 60 high school students and divided them into three groups.Group A listened to a five-minute piece of music intended to make them feel happy (a song titled "Don't Worry,Be Happy").Group B listened to a five-minute piece of music intended to make them feel sad (a song titled "Alone Again").Group C listened to no music and instead was asked to sit quietly for five minutes (thought to make them feel neutral). When a participant would come to her laboratory,Dr.Lonsbary would greet the participant and then ask him or her to draw a card.Participants who drew a 1,2,or 3 were assigned to Group A.Participants who drew a 4,5,or 6,were assigned to Group B.Participants who drew a 7,8,or 9,were assigned to Group C.The participants were then given an unlabeled CD to listen to based on their group assignment.The CD contained either the song selection or five minutes of silence.They were then escorted into a different room,where they were greeted by a research assistant who conducted the experiment.The research assistant sat the participants in front of a computer screen and told them that a list of 25 words would be displayed on the screen.They were instructed to listen to the CD with headphones while trying to memorize the list of words.All participants were given the same list of 25 words to remember. When five minutes had passed,the screen displayed a question asking them whether they felt happy,sad,or neutral.After the participant responded,a new screen was displayed asking them to type in all the words they could remember from the list of 25 words.All participants were given three minutes to type the words they remembered.Afterward,the participant was thanked and dismissed.In response to the mood question,a majority of Group A participants said they were happy,a majority of Group B participants said they were sad,and a majority of Group C participants said they were neutral in their mood.Dr.Lonsbary found the following results in response to the number of words remembered. -What type of design did Dr.Lonsbary use in her study?

Which of the following research designs is used to address possible selection effects?

Random selection enhances ________ and random assignment enhances ________.

The ability for a study to reveal a statistically significant difference between the levels of an independent variable when one truly exists is known as:

What is the primary difference between pretest/posttest designs and within-groups designs?

Explain the difference between full counterbalancing and partial counterbalancing.Why would a researcher choose partial counterbalancing over full counterbalancing?

Explain why experiments are better than your own personal experience at making causal claims.

An independent-groups design is also known as a ________.

Dr.Phillips is a cognitive-developmental psychologist who studies how children learn mathematical principles.His current interest is in studying how children learn multiplication.He recruits 54 second-graders who have not yet learned how to multiply numbers to participate in his study.He is curious as to whether different teaching styles lead to better mastery of the subject.One condition (A)involves having students read a chapter on multiplication from their textbook.One condition (B)involves having students watch a video of cartoon characters explaining multiplication.One condition (C)involves having students being taught multiplication from a teacher.One condition (D)involves having students being taught multiplication by a fourth-grader.In all conditions,participants spend 30 minutes learning the fundamentals of multiplication and are then given the same 15-question multiplication test.The number of questions answered correctly is recorded.The data are below. -Name two ways that Dr.Phillips could avoid selection threat when he is assigning participants to conditions and explain why each of these methods avoids selection threat.