31) Which results for a set of classes suggest that there might have been a “testing†effect from the pretest? A) A B) B C) C D) D E) E Teachers Jack Black and Shannon Shack want to increase the percentage of high school freshmen who pass an algebra exam (dependent variable). They conduct experiments on five sets of classes (named A to E) in Toronto area schools. They randomly assign students and give a pretest in September followed by a post-test the following January. The treatment is teaching method. The experimental groups are taught with special in-class demonstrations and pictorial games-quizzes on computers, but no homework assignments, textbooks, or tests. The control groups are taught in the traditional manner with a textbook, homework, formulas on the blackboard, and tests. 32) Which set of classes suggests that the new method really helps students learn algebra better? A) A B) B C) C D) D E) E Teachers Jack Black and Shannon Shack want to increase the percentage of high school freshmen who pass an algebra exam (dependent variable). They conduct experiments on five sets of classes (named A to E) in Toronto area schools. They randomly assign students and give a pretest in September followed by a post-test the following January. The treatment is teaching method. The experimental groups are taught with special in-class demonstrations and pictorial games-quizzes on computers, but no homework assignments, textbooks, or tests. The control groups are taught in the traditional manner with a textbook, homework, formulas on the blackboard, and tests. 33) Which set of classes appears to have had serious “selection bias†problems in assignment to the experimental and control groups? A) A B) B C) C D) D E) E Teachers Jack Black and Shannon Shack want to increase the percentage of high school freshmen who pass an algebra exam (dependent variable). They conduct experiments on five sets of classes (named A to E) in Toronto area schools. They randomly assign students and give a pretest in September followed by a post-test the following January. The treatment is teaching method. The experimental groups are taught with special in-class demonstrations and pictorial games-quizzes on computers, but no homework assignments, textbooks, or tests. The control groups are taught in the traditional manner with a textbook, homework, formulas on the blackboard, and tests. 34) Looking at all five sets, which set of classes appears to be made up of a nonrandom sample of students from the Toronto area schools? A) A B) B C) C D) D E) E 35) Research Assistant Xavier Xed found a job working for a local mayoral candidate running for election. He decided to apply his knowledge about experiments to his new job and test whether the method of distributing campaign literature resulted in more people voting for a candidate. He distributed campaign literature about the mayoral candidate to the Stevenson neighbourhood in a bright blue envelope that a volunteer placed in each person’s front door. He distributed the same campaign literature about the candidate to the Fairwinds neighbourhood by mailing it in a plain white envelope that went to each address. He later learned that Stevenson was a low-income area of the city that was almost entirely Filipino, foreign-born, and 95 percent Catholic. Fairwinds was an upper-income area in the city and its residents were 100 percent white, Canadian-born Protestants. What problem with internal validity might threaten the results of his experiment? A) Selection bias B) History effect C) Experimental mortality D) Maturation E) Testing effect 36) If the time between the pretest and the post-test is very short, then A) the history effect is more likely to occur. B) the statistical regression effect is less likely to occur. C) the testing effect is more likely to occur. D) the maturation effect is less likely to occur. E) the statistical regression effect is more likely to occur. 37) What is a “placebo†in experimental research? A) When an experimenter deceives subjects about the experiment’s true nature, then later tells them what it is really about B) When subjects in a control group are treated the same as the subjects receiving the treatment C) When subjects in the control group receive a false or empty treatment so they do not adjust their behaviour to confirm the experimenter’s hypothesis D) When neither the subjects nor an assistant helping the experimenter know specifics about the treatment or how hypothesis is being tested E) When an event outside the experiment’s control occurs during the experiment and affects the dependent variable 38) What does the Hawthorne effect refer to? A) Research that takes place in a natural setting B) Research that takes place in an artificial setting C) A treatment that has no effect in an experiment. D) The effect that occurs when a researcher measures the dependent variable measure such that all the subjects get a perfect, or near perfect score. It means that by random chance alone the scores are likely to be lower the next time the same subjects are measured. E) A situation in which subjects react to the fact that they are in an experiment more than they react to the treatment 39) Field experiments, compared to laboratory experiments, generally have A) lower external validity and higher internal validity. B) higher external validity and lower internal validity. C) lower external validity and lower internal validity. D) higher external validity and higher internal validity. E) equal external and internal validity. 40) Professor Ronald Ronaldson conducted an experiment to test changes in sex roles due to spending an entire day reading about the achievements of great women artists and scientists. The experimental group read 15 articles about the achievements of great and wonderful women. The control group read 15 articles about cooking, automobiles, astronomy, and accounting. During the lunch break, subjects from the experimental and control groups met and talked about what they were reading. What internal validity problem may occur? A) Testing B) Maturation C) Diffusion of treatment D) Experimental mortality E) Hawthorne effect