Using the images attached of a study, answer the following question:1.What was the independent variable(s) in this study? Explain how you know. Student evaluations of courses and instructors arecommonplace at American universities. These evalu-ations are an important source of information for in-structors seeking to improve their teaching methods,for academic departments that wish to evaluate instruc-tors' teaching effectiveness, and for students makingdecisions about enrolling in a course. The influence ofstudent evaluations raises one obvious question: Arethey a reliable and valid source of information aboutcourse quality and instructor effectiveness?Compared to other proposed rating systems (e.g.,peer review), student evaluations might have supe-rior reliability and external validity (Cashin, 1995).Nevertheless, evaluations can be systematically biasedby a number of factors. We delineate these into twomain sources of influence, internal and external factors.Much of the interest in the reliability and validity ofstudent evaluations has centered on internal factors,factors that are more or less inherent to a course. Forexample, prior work has found that student evalua-tions are related to grading leniency (Greenwald &Gilmore, 1997) and the gender of the instructor (Ba-sow & Silberg, 1987). Other internal factors mightinclude the relative difficulty of the course, the avail-ability of course materials, the presentation of coursematerials, and so on. Because internal factors appearto be inextricably linked to an individual course, it isquite difficult to standardize them across courses.It is also possible that external factors, factors thatare entirely independent of the course, also influencestudent evaluations. Such factors are particular to theevaluation context and could include the timing, for-mat, and distribution of the evaluations, to name a few.Although the influence of external factors might seemintuitive (e.g., many instructors would not want to beevaluated after passing back an exam where studentsperformed poorly), there is little experimental evidenceabout their effects. This lack of evidence is somewhatsurprising, because, compared to internal factors, ex-ternal ones are far easier to control and manipulate.In this study, we address the effects of a single butpotentially widespread external influence on students'evaluations: whether students are offered candy beforecompleting their evaluations. We selected this exter-nal factor because it is both easily manipulated andbecause, based on an informal polling of colleagues,it is a fairly common practice when collecting eval-uations. In an attempt to control for potentially in-fluential internal factors, this study included studentswho were enrolled in the same lecture section of acourse, but who attended separate discussion sections.These sections met weekly on the same day and wereled by the same teaching assistant. We also attemptedto control for confounding external variables: Eachdiscussion section had a maximum enrollment of 20students, each section met on Friday mornings, all stu-dents received the same amount of time to completetheir evaluations, and the same experimenter adminis-tered all evaluations. The experimental manipulationinvolved offering students in half of the discussion sec-tions a piece of chocolate prior to completing theirevaluations. The students in the other sections werenot offered chocolate. If this positive external eventaffects students' evaluations, then students who are offered chocolate might rate the course and its instruc-tor more favorably.MethodParticipantsThe participants were 98 undergraduates from theUniversity of Illinois at Chicago from three differentclasses, two statistics classes (n = 34 and 29) and oneresearch methods class (n = 35). The same instructortaught all three classes. Each class required studentsto enroll in one of two Friday discussion sections ofapproximately equal size. The same teaching assistantled sections for each class (with different teaching as-sistants serving each of the three classes).ProcedureDuring the ninth week of instruction, all partici-pants completed an informal midsemester evaluationabout the lecture section of their course (the discussionsections were not evaluated at this time). An experi-menter who was not involved with the course adminis-tered the evaluations at the beginning of class. Studentsrequired approximately 10 min to complete evalua-tions. All students received the same nine-questionform (see Table 1). For each question, the studentprovided a rating from 1 (very poor) to 5 (excellent).The questions pertained to various dimensions of thecourse and instructor and were adapted from questionsappearing in the standard end-of-semester evaluationform used by the University of Illinois at Chicago.The experimental manipulation involved the treat-ment of students prior to their completion of the eval-uation forms. In half of the sections, students had theopportunity to take a small bar of chocolate from a bagpassed around by the experimenter before the evalu-ations began. Importantly, the experimenter told par-ticipants in these sections that he had chocolate leftfrom another function that he "just wanted to get ridof' and that the students were welcome to take a piece.The fact that the chocolate was the property of the ex-perimenter was emphasized so participants would notmisattribute the chocolate as a gift from their instruc-tor or teaching assistant. Across the three courses, werandomly assigned which discussion section (the firstor second of the day) would be in the chocolate orcontrol conditions.ResultsThe results were analyzed in a 2 (condition:chocolate vs. control) x 3 (class: statistics 1 vs.statistics 2 vs. research methods) × 9 (evaluationform question: 1 to 9) ANOVA, with condition andclass as between-subject variables and evaluationform question as a within-subjects variable. Thisanalysis revealed a main effect of class, F(2, 92)5.60, p

Question

Using the images attached of a study, answer the following question:1.What was the independent variable(s) in this study? Explain how you know. Student evaluations of courses and instructors arecommonplace at American universities. These evalu-ations are an important source of information for in-structors seeking to improve their teaching methods,for academic departments that wish to evaluate instruc-tors' teaching effectiveness, and for students makingdecisions about enrolling in a course. The influence ofstudent evaluations raises one obvious question: Arethey a reliable and valid source of information aboutcourse quality and instructor effectiveness?Compared to other proposed rating systems (e.g.,peer review), student evaluations might have supe-rior reliability and external validity (Cashin, 1995).Nevertheless, evaluations can be systematically biasedby a number of factors. We delineate these into twomain sources of influence, internal and external factors.Much of the interest in the reliability and validity ofstudent evaluations has centered on internal factors,factors that are more or less inherent to a course. Forexample, prior work has found that student evalua-tions are related to grading leniency (Greenwald &Gilmore, 1997) and the gender of the instructor (Ba-sow & Silberg, 1987). Other internal factors mightinclude the relative difficulty of the course, the avail-ability of course materials, the presentation of coursematerials, and so on. Because internal factors appearto be inextricably linked to an individual course, it isquite difficult to standardize them across courses.It is also possible that external factors, factors thatare entirely independent of the course, also influencestudent evaluations. Such factors are particular to theevaluation context and could include the timing, for-mat, and distribution of the evaluations, to name a few.Although the influence of external factors might seemintuitive (e.g., many instructors would not want to beevaluated after passing back an exam where studentsperformed poorly), there is little experimental evidenceabout their effects. This lack of evidence is somewhatsurprising, because, compared to internal factors, ex-ternal ones are far easier to control and manipulate.In this study, we address the effects of a single butpotentially widespread external influence on students'evaluations: whether students are offered candy beforecompleting their evaluations. We selected this exter-nal factor because it is both easily manipulated andbecause, based on an informal polling of colleagues,it is a fairly common practice when collecting eval-uations. In an attempt to control for potentially in-fluential internal factors, this study included studentswho were enrolled in the same lecture section of acourse, but who attended separate discussion sections.These sections met weekly on the same day and wereled by the same teaching assistant. We also attemptedto control for confounding external variables: Eachdiscussion section had a maximum enrollment of 20students, each section met on Friday mornings, all stu-dents received the same amount of time to completetheir evaluations, and the same experimenter adminis-tered all evaluations. The experimental manipulationinvolved offering students in half of the discussion sec-tions a piece of chocolate prior to completing theirevaluations. The students in the other sections werenot offered chocolate. If this positive external eventaffects students' evaluations, then students who are offered chocolate might rate the course and its instruc-tor more favorably.MethodParticipantsThe participants were 98 undergraduates from theUniversity of Illinois at Chicago from three differentclasses, two statistics classes (n = 34 and 29) and oneresearch methods class (n = 35). The same instructortaught all three classes. Each class required studentsto enroll in one of two Friday discussion sections ofapproximately equal size. The same teaching assistantled sections for each class (with different teaching as-sistants serving each of the three classes).ProcedureDuring the ninth week of instruction, all partici-pants completed an informal midsemester evaluationabout the lecture section of their course (the discussionsections were not evaluated at this time). An experi-menter who was not involved with the course adminis-tered the evaluations at the beginning of class. Studentsrequired approximately 10 min to complete evalua-tions. All students received the same nine-questionform (see Table 1). For each question, the studentprovided a rating from 1 (very poor) to 5 (excellent).The questions pertained to various dimensions of thecourse and instructor and were adapted from questionsappearing in the standard end-of-semester evaluationform used by the University of Illinois at Chicago.The experimental manipulation involved the treat-ment of students prior to their completion of the eval-uation forms. In half of the sections, students had theopportunity to take a small bar of chocolate from a bagpassed around by the experimenter before the evalu-ations began. Importantly, the experimenter told par-ticipants in these sections that he had chocolate leftfrom another function that he &#34;just wanted to get ridof' and that the students were welcome to take a piece.The fact that the chocolate was the property of the ex-perimenter was emphasized so participants would notmisattribute the chocolate as a gift from their instruc-tor or teaching assistant. Across the three courses, werandomly assigned which discussion section (the firstor second of the day) would be in the chocolate orcontrol conditions.ResultsThe results were analyzed in a 2 (condition:chocolate vs. control) x 3 (class: statistics 1 vs.statistics 2 vs. research methods) × 9 (evaluationform question: 1 to 9) ANOVA, with condition andclass as between-subject variables and evaluationform question as a within-subjects variable. Thisanalysis revealed a main effect of class, F(2, 92)5.60, p < .05; a main effect of question, F(8, 92)16.02, p < .05; and an interaction between class andquestion, F(2, 92) = 2.19, p <.05. These effects aretangential to the main question of this study and arenot discussed further. The question of main interestis whether the participants offered chocolate before=

Accepted Answer

An independent variable is a basic idea in both statistical and experimental studies. It's a thing…

Using the images attached of a study, answer the following question: 1.What was the independent variable(s) in this study? Explain how you know.