Rina is conducting a longitudinal study examining the impact of parenting on children as they move from middle childhood into adolescence. She starts with a sample of fourth grade children and tests them annually until they are in ninth grade. At the ninth-grade appointment, only 62 families show up. What threat to internal validity is relevant here?

Dr. Dormeur studies sleep and sleep disorders. She is curious as to whether technology exposure before bedtime causes people to fall asleep more slowly. 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 are asked to play an online game (Candy Crush) on an iPad for 10 minutes prior to going to bed. In the second condition (B), participants are asked to use an iPad to read an article that discusses tricks and tips for improving one’s score on Candy Crush (which takes about 10 minutes). In the third condition (C), participants are asked to read a newspaper article about the inventor of Candy Crush (which takes about 10 minutes). 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. Dormeur’s study?

Anton and his friends are discussing a study he read about in his developmental psychology class. In the study, the researcher made the claim that most middle school students who are bullied have low self-esteem. Clarissa questions the study, saying, “I am not sure that I am convinced. I am not sure you can really measure being bullied.” Quinn also questions the study, saying, “Which middle school students did they study? I am curious if they included both private and public school students.” Manish is also curious about the study, asking, “I wonder how strong the relationship is between bullying and self-esteem. Could you predict one from the other?” Manish’s concern is addressing which of the following?

You are reading the abstract of an article that says, “There is no correlation between the quality of the instruction and the test scores of the students.” Based on this, you know that the association between the two variables was

Research that creates rich descriptions rather than simplifying data into numbers is

Anderson is reading his morning paper and sees the following headline: “Men Should Avoid Rock Music When Playing Board Games.” (This headline is based on a study conducted by Fancourt, Burton, & Williamon, 2016.) In the study, men and women played the game “Operation” when listening to different types of music. Male participants performed worse when listening to AC/DC than when listening to Mozart, but female participants’ performance did not differ based on music. Which of the following is a constant in this study?

Anderson is reading his morning paper and sees the following headline: “Men Should Avoid Rock Music When Playing Board Games.” (This headline is based on a study conducted by Fancourt, Burton, & Williamon, 2016.) In the study, men and women played the game “Operation” when listening to different types of music. Male participants performed worse when listening to AC/DC than when listening to Mozart, but female participants’ performance did not differ based on music. Which of the following is a variable in this study?

Professor Kramer has decided to measure how happy his students are with his teaching this semester. He is teaching two classes: Psychology and Law and Introduction to Neuroscience. He gives his students a survey. Dr. Kramer plans to give his survey only to his Psychology and Law students because he sees them on Mondays, Wednesdays, and Fridays, and he can spare the class time (unlike in his Introduction to Neuroscience class, which only meets on Tuesdays and Thursdays). Which of the following is true?

An operational definition

Male true vocal folds are between [number1] in length. In average, they vibrate at [number2] Hz during speech.