Dr. Bauer’s Fun Variable Sheet

I. Three levels of variables

A. Construct ----à Research--à Operational Definitions

1. The IV and the DV each have these 3 levels

B. Conceptual (Construct) Variables

1. This is when concepts are typically vague-not well defined or meaningful to anyone. Eg. Intelligence, artistic ability, memory, personality, aggressiveness.

2. This refers to general abstractions or theoretical level of the variable (the largest picture).

3. May be measured in many ways--- Depends on how you define it.

C. Research Hypothesis

1. Translates an abstract (construct) into something more specific.

2. Makes it more concretes

a. Intelligence might be a component of creative intelligence

b. Artistic ability-might be a specific part of Mass Media

c. Memory might be short or long term memory

D. Operational Definition of Concept

1. Operational: The method used to measure the concept

2. The IV-Tells how the conceptual variable is defined in the experiment

3. For the DV-tells how the behavior or change is to be measured—the data that is recorded.

Relationship Between Concepts and Measures of Concepts

Level of Anlaysis	Type of Variable	Type of Variable
	Independent	Dependent
Conceptual Hypothesis	Intelligence	Memory
Research Hypothesis	Academic (school based)	Recall Memory
Measurement	# of Correct items on a test	# of nouns recalled

Persons with High IQ scores will Recall more nouns than those with low IQ scores. (1-tailed)

II. Operationalizing independent and dependent variables

A. How we operationalize IV’s and DV’s depends on the nature of the variables.

B. Independent Variables (IV)

1. Predictor: The feature of the study used to predict or explain the (outcome) behavior (DV).

2. Researcher has some control over these variables ---although the degree of control may vary.

3. IV’s may be manipulated or measured

a. Maniupulated

a. Variable researchers controls or determines what the subject is exposed to.

b. Examples

i. Type of medicine used.

ii. Type of therapy used

iii. Amount of Stimulations

iv. Number of learning trials

v. Exposure minutes

b. Measured

a. Characteristics of subject-

i. Used to classify Subject (Young/Old), (Male/Female); Age or as a continuous measure (Personality test score), (AGE)

ii. Examples- Traits of subjects )age (2-, 4-,6 month olds), Weight, Eye color, Scores on psychological behavioral scale-intelligence, self-esteem, personality, introversion, extroversion.

4. Examples of IV’s on each of the 4 rating scales

Scale of Measurement

Independent Variables	Nominal	Ordinal	Interval	Ratio
Manipulated Levels	Treatment (yes/no)	Instructions (Clear/Moderate/Vague	Depression Score on Beck Depression Inventory	Hear rate (recorded as beats per minutes)
Measured Levels	Gender (F/M)	Age (0-1,1-2,2-5 years	Intro- or Extroversion (Self Report Score)	Reaction Time (in minutes)

C. Dependent Variables

1. Criterion: Characteristic the researcher is accounting for, predicting (Usually some behavior being measured)

2. Because it is the behavior expressed by the subject, this variable is dependent on the subject’s performance

a. Subject has at least some control over the response of interest to the researcher

b. Experimenter observes, measures, records the response or score of interest.

3. Measurement may be Qualitative or Quantitative

a. Qualitative

a. Nominal Scale only

b. Is a tally, a count; each person can contribute only one value to the count (data)

b. Quantiative

a. Ordinal, Interval, Ratio scales of measurement

b. Anything you can do an arithmetic calculation beyond just summing

4. Three Forms of Quantitative Data

a. Frequency (How often or how much in terms of behavior)-Ratio Scale-# correct, %correct, prop correct

b. Duration (time Measures) Ratio Scale-Reaction Time, Duration in seconds

c. Amplitude/Force-Interval Scale,Rating Scales, Polygraph Record

5. Measurement scales and DV’s

Nominal	Ordinal	Interval	Ratio
Frequency, Tally Count	Likert Scales Preferences Ranked Rank in Triathlon BCS	Rating Scales: Self Esteem Introversion/Extroversion Depression IQ Scores	% Correct Reaction Time Height, Weight #wrong

III. Implications of Measurement

A. Measurement of DV-Type of Statistical Analysis applied to data

B. Measurement of IV- Selection type of Graphic Figure

1. 3 Types of Graphs to use

a. Bargraph: Used when IV that defines the x-axis represents a nominal or ordinal (discrete type of measurement)

b. Histogram or Frequency Polygram: Used when the IV that defines the x-axis represents an interval or ratio (quantitative-continuous) scale of measurement

2. Graphic figures reflect IV and DV are operationalized

a. DV always on the Y axis

b. IV always on the X axis

c. Can have several IV’s displayed a variety of ways.

C. Measurement of IV and DV are related to the Type of Conclusions or Interpretations made

IV. Interpretations

A. Goals of Research

1. Establish whether there are systematic relationships between two variables (IV and DV)

2. Control bias to facilitate understanding of what caused the relationship/change in behavior observed.

3. Establish generality

B. How well are goals met?

1. All research manages #1 well

2. A lot seek # 2 but do not truly achieve it

3. Only a few seek #3 in the strictest sense because very few generate their samples by randomly selecting from the population.

C. Types of research and how outcomes are interpreted

1. Related to the

a. Nature of the IV

b. The type of the DV

c. How subjects are placed in groups or exposed to the experiment

	Survey	Quasi-Experiment	True Experiment
Sample created by	NO random assignment	Random assignment of at lest 1 or 2 or more IV/s	Random Assignment of all IV’s
Independent Variable	Measured And/or Manipulated	Manipulated and Measured	Manipulated IV
Dependent Variable	Qualitative	Quantitative	Quantitative
Interpretation	Descriptive	Measured IV: Descriptive or Coorelation Manipulated IV: Cause and effect	Causal and Effect
Example: IV DV	Political Party and Gender Preferences	Gender and Training Method % correct on memory test	Amount of Drug (mg) and Type of Memory (Visual vs. Auditory) Reaction time in seconds

*Only a random study is true

*When you do a random study you are saying that your study is generalizable to the population and can my replicated by different researchers.

The “Wonder Drug” you developed did not double your IQ but it did double the subjects reaction time. (Null accepted with interesting findings)