5 4 Points An implementation threat to internal validity in a study comparing two methods is best controlled by: allowing teachers to select the method they will use. insisting that each teacher use the assigned method. making sure that all teachers are equal in ability. using many teachers with each method. Question 6 4 Points Construct validation involves: content-related evidence. criterion-related evidence. assessing evidence on predictions made from theory. All of these answers are correct. Question 7 4 Points Data-collection procedures that involve no intrusion into the naturally occurring course of events are called: norm-referenced instruments. sociometric devices. unobtrusive measures. interviews. Question 8 4 Points Errors of measurement are caused by: changes in test items. changes in the people who take a test. changes in the administration of the instrument. All of these answers are correct. Question 9 4 Points General reference tools are most useful in: locating original reports of research. reviewing the status of the research problem. evaluating the adequacy of previous studies. helping with methodological problems. Question 10 4 Points Identify a true statement about product rating scales. It is a subject-completed instrument. The product ratings can be done at any time. It is free from the rater's subjective judgments. It is the least preferred method used by researchers to collect data on p