Introduction to Research in Health and Human Sciences

Assignment: Identification of Study Variables (20 points)

Name: _________________________

For each of the following studies (Study One & Study Two): state a reasonable research question based on the study description, identify the Independent variable(s), Dependent variable and its Level of measurement, and one Controlled variable. You are given an example of the information being sought. 

Study One (10 points)

You are interested in look at the effects of strengthening exercise in adults with Down’s Syndrome. You randomly select twenty subjects (age range 19 – 35 years) from an adult workshop group. You measure the strength of the elbow flexors in pounds using a dynamometer prior to the start of an eight-week resistance training program. At the end of the eight weeks, you again test the strength of the elbow flexors.

Study Two (10 points)

You are interested in evaluating the effectiveness of three different education programs on caffeine consumption in young adults, age 18 – 24 years, who report that they drink at least one cup of coffee per day. You have a volunteer group of 30 subjects, and randomly assign each to one of the three education programs. Immediately after completion of the study, you determine how many have changed their consumption of caffeine (measured as change/no change). You re-interview the participants six months after completion of the program to determine if there has been a change in drinking habits.

Example Study

You wish to know if a new technique is effective in reducing dizziness in women between the ages of 65 and 80 years old. You ask a group of older women coming into a clinic with a primary complaint of dizziness if they are interested in participating in a study on different exercises that can be used to treat dizziness. Thirty women between the ages of 65 and 80 years agree to participate in the study. They are then randomly assigned to one of two exercise groups (new technique versus standard technique). You measure the time they can stand on one leg (measured in seconds) prior to and after a three-week treatment regime. 

Solutions to the example study:

Research question: Is the new treatment technique more effective at improving balance in older women than the standard treatment as measured by the length of time spent in single limb stance?

Independent variable: The independent variables are the basis for comparisons. The independent variable in this study is the treatment type – which assumes one of two values: new or standard. 

Dependent variable: The dependent variables are the outcome measures. The dependent variable is the length of time each can spend standing on one leg measured in seconds. 

Level of measurement: Ratio.

Controlled variables: The variables controlled by the researcher include: age (specified an age range), gender, setting (clinic), means to evaluate balance (single limb stance), length of time of the treatment (3 weeks), and primary diagnosis.