Research Methods: Experimental and Non-Experimental Designs

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Questions and Answers

What is a characteristic of the experimental method in research?

The researcher cannot control the independent variable

There is only one independent variable

The dependent variable is not measured

The researcher can manipulate the independent variable (correct)

What is the dependent variable in the example 'The effect of positive reinforcement on students' classroom participation'?

Students' self-concept

Students' classroom participation (correct)

Students' GPA scores

Positive reinforcement

Which of the following is a requirement of an experiment?

At least two independent variables

An independent variable and dependent variable(s) (correct)

A non-experimental design

Only one dependent variable

Which of the following is an example of a non-experimental method?

The relationship between UAEU students' self-concept and their GPA scores Signup and view all the answers

What is the main difference between experimental and non-experimental methods?

The researcher's ability to control the independent variable Signup and view all the answers

What is the purpose of the class activity in the text?

To differentiate between experimental and non-experimental methods Signup and view all the answers

What is the primary goal of balancing in an experiment?

To make sure that, on average, the participants in each condition are essentially the same Signup and view all the answers

What is the main reason why researchers cannot make individuals in the different conditions exactly the same?

Because of the natural variation in human characteristics Signup and view all the answers

What is the purpose of random assignment to conditions in an experiment?

To create, on average, equivalent groups of participants Signup and view all the answers

What can researchers rule out through the use of random assignment to conditions?

Alternative explanations for a study's findings related to subject characteristics Signup and view all the answers

What is the outcome of balancing participants' characteristics across the conditions of the experiment?

On average, equivalent groups of participants Signup and view all the answers

What is the main advantage of using balancing in an experiment?

It allows researchers to control for participant characteristics Signup and view all the answers

What is the main problem with assigning intact groups to conditions in an experiment?

Individual differences among groups are not balanced Signup and view all the answers

What are practical considerations that can confound an experiment?

The number of participants in each session Signup and view all the answers

What is the term for the variables that are not of interest in the experiment but can affect the outcome?

Extraneous variables Signup and view all the answers

What is the method used to control extraneous variables?

Balancing or holding conditions constant Signup and view all the answers

In an experiment, why is it important to control extraneous variables?

To increase the validity of the experiment Signup and view all the answers

What is the consequence of not controlling extraneous variables in an experiment?

The results of the experiment will be confounded Signup and view all the answers

What is a possible explanation for the mean difference observed in the sample?

The observed difference is due to chance Signup and view all the answers

What is a limitation of any individual experiment?

Limited external validity Signup and view all the answers

Why is research with college student participants often criticized?

Due to low external validity Signup and view all the answers

What is a way to increase external validity of findings?

Replicating the experiment in a new setting Signup and view all the answers

What is important for researchers to include in their experiments in order to increase external validity?

A representative sample and situation Signup and view all the answers

What is a question of external validity that researchers may ask?

Would the same findings occur with different settings? Signup and view all the answers

What is the primary reason researchers cannot make causal inferences in a natural groups design?

The independent variable is not manipulated Signup and view all the answers

Which of the following characteristics is an example of a social demographic characteristic?

Ethnicity Signup and view all the answers

What is the issue with comparing the occupational functioning of schizophrenics and non-schizophrenics in a natural groups design?

The groups are not matched on other variables Signup and view all the answers

Which type of design is used when the groups are formed naturally, and the researcher cannot randomly assign participants to these groups?

Natural groups design Signup and view all the answers

What is the independent variable in the example comparing the occupational functioning of schizophrenics and non-schizophrenics?

Schizophrenic vs. non-schizophrenic Signup and view all the answers

Why can't researchers randomly assign participants to groups in a natural groups design?

Because the groups are formed naturally Signup and view all the answers

Study Notes

Experimental and Non-Experimental Methods

Experimental method: researcher can manipulate the independent variable (the cause), e.g., the effect of positive reinforcement on students' classroom participation.
Non-experimental method: researcher cannot manipulate the independent variable (the cause), e.g., the relationship between UAEU students' self-concept and their GPA scores.

Experimental Research

An experiment must include: an independent variable (IV) and dependent variable(s) (DVs).
Balancing: a technique used to control for variables that cannot be held constant, such as participant characteristics, to make sure participants in each condition are essentially the same before the experiment begins.
Methods of balancing: random assignment to conditions, to create equivalent groups of participants in the experimental conditions.

Threats to Internal Validity

Extraneous variables: practical considerations that can confound an experiment, e.g., number of participants in each session, different experimenters, different rooms.
Examples of extraneous variables: experimenter effects, different experimenters conducting an experiment.
Control of extraneous variables: balancing or holding conditions constant.

External Validity

External validity refers to the extent to which findings from an experiment can be generalized to individuals, settings, and conditions beyond the scope of a specific experiment.
Limitations of external validity: individual experiments have limited external validity, but replication in new experiments can increase external validity.
Questions of external validity: would the same findings occur in different settings, with different conditions, or with different participants?

Natural Groups Designs

Natural groups design: a design in which the groups (conditions) are formed naturally, rather than through random assignment, e.g., comparing occupational functioning of schizophrenics and normal controls.
Causal inferences: cannot be made when using a natural groups design, as groups may differ in other ways beyond the independent variable.
Limitations of natural groups design: cannot control for extraneous variables, making it difficult to establish cause-and-effect relationships.

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Description

Test your understanding of experimental and non-experimental methods in research, including the manipulation of independent variables and their effects on dependent variables. Learn about the differences between these two methods and how they are applied in various research studies.