The differences between the simple quasi-experimental ...

[neverstopbelieb]

The differences between the simple quasi-experimental pretest-posttest design and an experimental version of the same design with a control group, in which there was random assignment to group, would be which of the following?
 
  (Select all that apply.)
  a. The experimental design controls for more variables.
  b. Subjects are blind to group assignment in the experimental design.
  c. There is now a means of two-group comparison.
  d. The design controls for changes due to maturation or history.
  e. The researcher collects data more frequently.

Question 2

Methodological designs are used to develop the validity and reliability of instruments to measure constructs used as variables in research. The process is lengthy and complex.
 
  The average length of researcher time required to develop a research tool to the point of appropriate use in a study is five years. Methodological studies include assessment of content validity, evaluation of the conceptual structure of a scale, construct validity, and assessment of reliability. A researcher is developing a tool to measure pre-delinquent behaviors in pre-adolescence. He has already reviewed the literature, gathered qualitative data from experts, pilot-tested hundreds of pre-delinquent preadolescents, and analyzed the findings. It is clear that the tool actually measures what it is supposed to measure. This reflects the tool's
  a. Validity
  b. Utilizability
  c. Reliability
  d. Lack of bias

[macybarnes]

Answer to Question 1

ANS: A, C, D
The one-group pretest-posttest design is one of the more commonly used quasi-experimental designs. However, it has such serious weaknesses that findings are often uninterpretable. Pretest scores cannot adequately serve the same function as a comparison group. Events can occur between the pretest and posttest that alter responses to the posttest. The original, or classic, experimental design, or pretest-posttest control group design, is still the most commonly used experimental design. There are two randomized groups, one receiving the experimental treatment and one receiving no treatment, a placebo treatment, or the routine or standard care. By comparing pretest scores and the groups' demographic characteristics, one can evaluate the effectiveness of randomization in providing equivalent groups. The researcher implements the treatment or independent variable under very controlled conditions. The dependent variable is measured twice, before and after the manipulation of the independent variable.

Answer to Question 2

ANS: A
Methodological designs are used to develop the validity and reliability of instruments to measure constructs used as variables in research. The process is lengthy and complex and should begin with a thorough literature review. Qualitative data is often collected when there is not much known about a construct and will allow the researcher to identify key factors/concepts associated with the construct which might be used to create a checklist.
Validity refers to a tool's ability to measure what the researcher intends it to measure.