Instruction: For each selection, your task is to determine whether a threat to internal validity is present. If you feel internal validity is compromised, then you must identify which threat to internal validity is present. One of the selections has no threat to internal validity. Selection 1. Barry, a basketball coach, wanted to decrease the number of turnovers made by his team. He believed that a starting player should lose the ball to the opposing team no more than two times per game. Earlier statistics indicated that this was a reasonable goal for all his starters, although no one player achieved it consistently from game to game. His new coaching strategy involved the following: In the team meeting following a game, Barry read out loud the number of turnovers committed by each player, and he publicly criticized those starting players who did not meet the goal. He found that chastised players tended to do better the next game, and, because of its apparent success, he continued with his new coaching strategy. Is a threat present (Yes/No)? If yes, identify the threat: Selection 2. Based on her own experience, Professor Lucas strongly believed that study groups enhance student learning. During the very first class she taught she encouraged her students to contact Joe, a Learning Skills Specialist at Counseling Services. She told them that Joe and his colleagues would help them form groups, make. arrangements for where and when to meet, and supervise the meetings. About half the students took Professor Lucas' advice. They met once a week in their respective study groups for the duration of her course. Counseling Services kept a record of participating students, which Professor Lucas used for her data analysis. Her dependent measure was the final exam grade, which was marked by her teaching assistant She discovered that students who met weekly with study groups (Study Group condition) scored two letter grades higher than students who did not meet weekly with study groups (Control condition). She attributed the higher exams scores to the study group meetings. Is a threat present (Yes/No)? If yes, identify the threat: Selection 3. Waitpersons at two affiliated restaurants with poor sales figures had asked for raises in hourly pay that the owners could not afford. The owners wondered if there could be an alternative mutually beneficial arrangement between them and their employees, and so they requested help from researchers in the field of organizational behavior management. For the next four pay periods, the researchers recorded the mean dollar earned per hour of work (wages), a statistic important to the waitpersons, and sales per labor hour (productivity), a statistic important to the owners. Then, during a staff meeting at each restaurant, the waitpersons were told that each of them would be paid 7% of their gross sales rather than a fixed amount per hour. This pay change was scheduled to start concurrently with a new "two-for-one special" promotion in local newspapers. Data continued to be recorded for four more pay periods. The researchers discovered, much to the owners' delight, that productivity rose by 15% at Restaurant A and 12% at Restaurant B (and much to the waitpersons' delight, wages increased by 30% at Restaurant A and 20% at Restaurant B). We can conclude that the new performance contingent pay system improved the waitpersons' productivity, a conclusion bolstered by the fact that the effect was replicated across the two restaurants. Is a threat present (Yes/No)? If yes, identify the threat: Selection 4. Researchers were interested in whether modeling would improve an infant's ability to make a neat pincer grasp, which involves gripping a small object with the thumb and one finger. The participants, whose beginning age was approximately 8 months old, were observed in the laboratory during two, one-hour sessions. In the first session, the infants' parents presented them with a pea every five minutes along with a verbal prompt to pick it up. Then, in the next session about two months later, the infants' parents used this same procedure, but they also modeled the correct behavior immediately prior to the verbal prompt. The infants used the appropriate motor response to pick up the pea about 10% of time in the first session and about 45% percent of the time in the second session. We can conclude that modeling increased the likelihood with which infants made a neat pincer grasp. Is a threat present (Yes/No)? If yes, identify the threat: Instruction: For each selection, your task is to determine whether a threat to internal validity is present. If you feel internal validity is compromised, then you must identify which threat to internal validity is present. One of the selections has no threat to internal validity. Selection 1. Barry, a basketball coach, wanted to decrease the number of turnovers made by his team. He believed that a starting player should lose the ball to the opposing team no more than two times per game. Earlier statistics indicated that this was a reasonable goal for all his starters, although no one player achieved it consistently from game to game. His new coaching strategy involved the following: In the team meeting following a game, Barry read out loud the number of turnovers committed by each player, and he publicly criticized those starting players who did not meet the goal. He found that chastised players tended to do better the next game, and, because of its apparent success, he continued with his new coaching strategy. Is a threat present (Yes/No)? If yes, identify the threat: Selection 2. Based on her own experience, Professor Lucas strongly believed that study groups enhance student learning. During the very first class she taught she encouraged her students to contact Joe, a Learning Skills Specialist at Counseling Services. She told them that Joe and his colleagues would help them form groups, make. arrangements for where and when to meet, and supervise the meetings. About half the students took Professor Lucas' advice. They met once a week in their respective study groups for the duration of her course. Counseling Services kept a record of participating students, which Professor Lucas used for her data analysis. Her dependent measure was the final exam grade, which was marked by her teaching assistant She discovered that students who met weekly with study groups (Study Group condition) scored two letter grades higher than students who did not meet weekly with study groups (Control condition). She attributed the higher exams scores to the study group meetings. Is a threat present (Yes/No)? If yes, identify the threat: Selection 3. Waitpersons at two affiliated restaurants with poor sales figures had asked for raises in hourly pay that the owners could not afford. The owners wondered if there could be an alternative mutually beneficial arrangement between them and their employees, and so they requested help from researchers in the field of organizational behavior management. For the next four pay periods, the researchers recorded the mean dollar earned per hour of work (wages), a statistic important to the waitpersons, and sales per labor hour (productivity), a statistic important to the owners. Then, during a staff meeting at each restaurant, the waitpersons were told that each of them would be paid 7% of their gross sales rather than a fixed amount per hour. This pay change was scheduled to start concurrently with a new "two-for-one special" promotion in local newspapers. Data continued to be recorded for four more pay periods. The researchers discovered, much to the owners' delight, that productivity rose by 15% at Restaurant A and 12% at Restaurant B (and much to the waitpersons' delight, wages increased by 30% at Restaurant A and 20% at Restaurant B). We can conclude that the new performance contingent pay system improved the waitpersons' productivity, a conclusion bolstered by the fact that the effect was replicated across the two restaurants. Is a threat present (Yes/No)? If yes, identify the threat: Selection 4. Researchers were interested in whether modeling would improve an infant's ability to make a neat pincer grasp, which involves gripping a small object with the thumb and one finger. The participants, whose beginning age was approximately 8 months old, were observed in the laboratory during two, one-hour sessions. In the first session, the infants' parents presented them with a pea every five minutes along with a verbal prompt to pick it up. Then, in the next session about two months later, the infants' parents used this same procedure, but they also modeled the correct behavior immediately prior to the verbal prompt. The infants used the appropriate motor response to pick up the pea about 10% of time in the first session and about 45% percent of the time in the second session. We can conclude that modeling increased the likelihood with which infants made a neat pincer grasp. Is a threat present (Yes/No)? If yes, identify the threat