Final: Dependent and Independent Variables

A researcher would like to determine whether regular doses of St. John's Wort have an effect on memory for college students. A group of 50 Chaffey College students is selected and each student is given a standardized memory test. Then each student takes a daily dose of St. John's Wort. At the end of six weeks, the students are once again given a memory test. The researcher intends to compare scores from the two tests to see whether there is any change in memory ability. b. For this study, describe the sample:

Chaffey College Students

A researcher would like to determine whether regular doses of St. John's Wort have an effect on memory for college students. A group of 50 Chaffey College students is selected and each student is given a standardized memory test. Then each student takes a daily dose of St. John's Wort. At the end of six weeks, the students are once again given a memory test. The researcher intends to compare scores from the two tests to see whether there is any change in memory ability. For this study, describe the population:

College Students

A researcher studying the effects of environmental color on anger asks subjects to sit alone in a waiting room for 15 minutes at the beginning of the experiment. The time s/he really sits in room is 25 minutes. Half of the subjects are assigned to a room with bright red walls. The other half of the subjects are assigned to a room with light blue walls. After the 25 minutes, each subject is brought into the lab and given an anger assessment questionnaire. Identify the independent variable in the above experiment:

Environmental color

A researcher would like to examine the relationship between exposure to light and mood. In one section of an office building, the intensity of the lighting is increased by 50% for a two week period and in another section of the same building, the lighting is reduced by 25% for the same time period. At the end of the two week period the workers in both sections are given a mood inventory test. a. Identify the independent variable in the above experiment:

Exposure to light.

Dr, Espumosa is interested in determining whether listening to Arabic music will improve student learning. He randomly divides 50 high school students into two groups. In Group 1, the students learned new material while listening to the music. Group 2 received equal learning time for the new material but DID NOT listen to the music. After the learning period, each group took the same "learning improvement" test. The test scores for Group 1 were better (higher) than Group 2. c. What is the dependent variable in this study?

Learning improvement test scores

Say you are interested in how well students perform on a standardized math-achievement test after they have completed a six-week math unit in either a computer-assisted class, a videotaped class or a regular classroom. b. What are the levels of this IV?

Level 1: Computer-assisted class Level 2: Videotaped class Level 3; Regular classroom

A researcher would like to examine the relationship between exposure to light and mood. In one section of an office building, the intensity of the lighting is increased by 50% for a two week period and in another section of the same building, the lighting is reduced by 25% for the same time period. At the end of the two week period the workers in both sections are given a mood inventory test. c. What are the levels of the I.V.?

Level 1: Lighting reduced by 25% Level 2: Lighting reduced by 50%

A researcher studying the effects of environmental color on anger asks subjects to sit alone in a waiting room for 15 minutes at the beginning of the experiment. The time s/he really sits in room is 25 minutes. Half of the subjects are assigned to a room with bright red walls. The other half of the subjects are assigned to a room with light blue walls. After the 25 minutes, each subject is brought into the lab and given an anger assessment questionnaire. b. Levels of the I.V.?

Level 1: Room with bright red walls Level 2: Room with light blue walls.

Gomez Research & Associates are interested in testing the relationship between voice pitch of a political candidate and electability. After randomly selecting American voters ages 35 and older from all United States, 30 participants are randomly assigned to three groups (10 in each group, of course) to listen to speech recordings by Candidate X. Group 1 listens to a speech recording by the candidate in low pitch. Group 2 listens to a speech recording by the candidate in mid-range pitch. Group 3 listens to a speech recording by the candidate in high pitched voice. The researchers proceed to measure the rate of candidate's electability in each instance. b. What are the levels of this IV?

Level 1: Speech recording by candidate in low pitch Level 2: Speech recording by candidate in mid-range pitch Level 3: Speech recording by candidate in high pitch

Dr, Espumosa is interested in determining whether listening to Arabic music will improve student learning. He randomly divides 50 high school students into two groups. In Group 1, the students learned new material while listening to the music. Group 2 received equal learning time for the new material but DID NOT listen to the music. After the learning period, each group took the same "learning improvement" test. The test scores for Group 1 were better (higher) than Group 2. b. What are the levels of this IV?

Level 1: learning new material while listening with music Level 2: Learning new material while not listening to music

Say you are interested in how well students perform on a standardized math-achievement test after they have completed a six-week math unit in either a computer-assisted class, a videotaped class or a regular classroom. c. What is the dependent variable in this study?

Math achievement test scores

A researcher would like to determine whether regular doses of St. John's Wort have an effect on memory for college students. A group of 50 Chaffey College students is selected and each student is given a standardized memory test. Then each student takes a daily dose of St. John's Wort. At the end of six weeks, the students are once again given a memory test. The researcher intends to compare scores from the two tests to see whether there is any change in memory ability. d. What is the DV?

Memory ability scores

Say you are interested in how well students perform on a standardized math-achievement test after they have completed a six-week math unit in either a computer-assisted class, a videotaped class or a regular classroom .a. What is the independent variable in this study?

Method of class

A researcher would like to examine the relationship between exposure to light and mood. In one section of an office building, the intensity of the lighting is increased by 50% for a two week period and in another section of the same building, the lighting is reduced by 25% for the same time period. At the end of the two week period the workers in both sections are given a mood inventory test. b. Identify the dependent variable in the above experiment:

Mood inventory test scores.

Gomez Research & Associates are interested in testing the relationship between voice pitch of a political candidate and electability. After randomly selecting American voters ages 35 and older from all United States, 30 participants are randomly assigned to three groups (10 in each group, of course) to listen to speech recordings by Candidate X. Group 1 listens to a speech recording by the candidate in low pitch. Group 2 listens to a speech recording by the candidate in mid-range pitch. Group 3 listens to a speech recording by the candidate in high pitched voice. The researchers proceed to measure the rate of candidate's electability in each instance. c. What is the dependent variable in this study?

Rate of candidate's electability

A researcher studying the effects of environmental color on anger asks subjects to sit alone in a waiting room for 15 minutes at the beginning of the experiment. The time s/he really sits in room is 25 minutes. Half of the subjects are assigned to a room with bright red walls. The other half of the subjects are assigned to a room with light blue walls. After the 25 minutes, each subject is brought into the lab and given an anger assessment questionnaire. c. Identify the dependent variable in the above experiment:

Scores on the anger assessment

A researcher would like to determine whether regular doses of St. John's Wort have an effect on memory for college students. A group of 50 Chaffey College students is selected and each student is given a standardized memory test. Then each student takes a daily dose of St. John's Wort. At the end of six weeks, the students are once again given a memory test. The researcher intends to compare scores from the two tests to see whether there is any change in memory ability. c. What is the IV?

St. John's Wort

Dr, Espumosa is interested in determining whether listening to Arabic music will improve student learning. He randomly divides 50 high school students into two groups. In Group 1, the students learned new material while listening to the music. Group 2 received equal learning time for the new material but DID NOT listen to the music. After the learning period, each group took the same "learning improvement" test. The test scores for Group 1 were better (higher) than Group 2. a. What is the independent variable in this study?

Type of music

Gomez Research & Associates are interested in testing the relationship between voice pitch of a political candidate and electability. After randomly selecting American voters ages 35 and older from all United States, 30 participants are randomly assigned to three groups (10 in each group, of course) to listen to speech recordings by Candidate X. Group 1 listens to a speech recording by the candidate in low pitch. Group 2 listens to a speech recording by the candidate in mid-range pitch. Group 3 listens to a speech recording by the candidate in high pitched voice. The researchers proceed to measure the rate of candidate's electability in each instance. a. What is the independent variable in this study?

Voice pitch

A researcher would like to examine the relationship between exposure to light and mood. In one section of an office building, the intensity of the lighting is increased by 50% for a two week period and in another section of the same building, the lighting is reduced by 25% for the same time period. At the end of the two week period the workers in both sections are given a mood inventory test. d. Who are the subjects in this study?

Workers