PSYC 201 Midterm 2- Ch. 6&7

Research Strategy

General approach to reseach determined by the kind of question it hopes to answer

Descriptive Research Strategy

1. Focusses on individual variables
2. Intended to answer questions about the specific state of individual variables for a specific group of individuals

Linear Relationship

Data points produced by the changing values of two variables form a straight-line pattern

Curvilinear Relationship

consistent, preictable relationship between two variables but with a curved line

Positive Relationship

increases in one varabile tend to be accompanied by increases in the other

Negative Relationship

increases in one varabile tend to be accompanied by decreases in the other

Correlational Research Strategy

1. Only attempts to describe the relationship, not explain it
2. Each variable is measured with numerical scores

Experimental Research Strategy

1. Answer cause-and-effect questions about the relationship between two variables
2. Conducted with rigourous control to ensure unambiguous demonstration

Quasi-Experimental Research Strategy

1. Answer cause-and-effect questions about the relationship between two variables but can never produce unambiguous explanation
2. Uses some rigor and control but has a flaw

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Non-Experimental Research Strategy

1. Attempts to demonstrate relationship between variables but does not attempt to explain it
2. No rigor and control, no cause-and-effect explanation

Difference between Correlational and Non-experimental research

Correlational: 1 group, 2 variables

Non-Experimental: 2 groups, 1 variable

3 Aspects of a Research Study (decisions to be made)

1. Group vs individual
2. Same indiviuals vs different individuals
3. Number of variables included

Research Strategy

General approach and goals of a research study. Determined by the question to be addressed and the answer you hope to obtain

Research Design

General framework for conducting a study/ implimenting a research strategy

Research Procedure

Exact, step by step description of a specific research study

External validity

the extent to which we can generalize the results of a research study to people, settings, times, measures, and characteristics other than those used in the study

Threat to external validity

characteristics that limit the ability to generalize the results

3 types of generalization

1. from sample to general population
2. from one research study to another
3. from research study to real-world situation

Internal validity

produces a single, unambiguous explanation for the relationship betweeen two variables

Threat to internal validity

any factor that allows for an alternative explanation

Threats to generalizing across participants or Subjects

1. Selection bias
2. College students
3. Volunteer bias
4. Participant characteristics


1. Cross-Species generalizations

Threats to generalizing across features of a study

1. Novelty effect
2. Multiple Treatment Interference
3. Experimenter characteristics

Threats to generalizing across features of the measures

1. Sensitization
2. Generality across response measures
3. Time of measurement

Extraneous variable

any variable in a study other than the specific variables being studied

Confounding variable

an extraneous variable that changes systematically along with the two variables being studied. Produces an alternative explanation for the observed relationship (threat to internal validity)

Participant variable/Individual Differences

personal characteristics that differ from one individual to the next (height, weight, gender, age, IQ, personality)

Time Related Variable

variables that change as time goes by

Experimenter Bias

Experimenters expectations or personal beliefs influence the findings of a study

Double-blind and Single-Blind studies

minimize the potential for experimenter bias

Experimental Research Strategy Elements

1. **Manipulation:** Researcher manipulates one variable to create a set of two or more treatment conditions
2. **Measurement:** Second variable is measured to obtain a set of scores in each treatment condition
3. **Comparison:** Scores in one condition are compared to the scores in another. Consistent differences mean that the manipulation caused the changes
4. **Control:** All other variables are controlled to ensure they do not influence the variables being examined

Independent variable

Variable manipulated by the researcher

Treatment condition

Situation or environment characterized by one specific value of the manipulated variable. Experiment contains 2 or more

Levels

Different values of the independent variable

Dependent variable

Variable observed for changes to assess the effect of manipulating the independent variable

Extraneous variables

All variables in the study other than the independent and dependent variables

third-variable problem

relationship between two variables is coincidental not causational

Directionality problem

the existence of a relationship does not always explain the direction of the relationship

Manipulation

Identifying the specific values of the independent variable to be examined and creating treatment conditions to do so

Confounding variables

third variable that is allowed to change systematically along with the two variables being studied

Randomization

use of random process to help avoid a systematic relationship between two variables

Random assignment

the use of random process to assign participants to treatment conditions

Random process

all possible outcomes are equally likely

Experimental condition

conditions in which the treatment is administered

Control condition

the condition in which the treatment is not administered

no-treatment condition

condition in which participants do not receive the treatment being evaluated

placebo effect

positive response by a participant to an inert medication that has no effect on the body. they think the medication is effective

placebo control condition

participants receive a placebo instead of actual treatment

manipulation check

additional measure to assess how the participants perceived and interpreted the manipulation and/or assess the direct effect of the manipulation

important times for a manipulation check

1. Participant manipulations
2. subtle manipulations
3. placebo controls
4. Simulations

Simulation

creation of conditions within an experiment that simulate or closely duplicate the natural environment in which they occur

Mundane realism

Superficial, usually physical, characteristics of the simulation, which probably have little positive effect on external validity

Experimental realism

The psychological aspects of the simulation

Field study

research conducted in a place the participants percieve as the natural environment