Chapter 3The Study of Adult Development and

Aging: Research Methods

Research Methods Research often starts with a hunch about a phenomenon.

Example hunch: Playing games that are cognitively challenging helps people retain their mental sharpness.

In order to conduct research, one must form a hypothesis, a testable statement that predicts an outcome. Example hypothesis: The more often people play games, the

faster they will be at solving problems.

Research Methods:Surveys

Surveys involve asking a sample of people about experiences, attitudes, or opinionsExample: Ask respondents how often they play games and to self-rate their problem-solving ability.

Simple CorrelationalResearch Design

A correlational study looks for a consistent relationship between two phenomena

Correlation: A statistical measure of how strongly two variables are related to one another.

Correlation coefficients can range from -1.0 to +1.0.

Direction of correlationsPositive correlationsAn association between increases in one variable and increases in another, or decreases in one variable and decreases in the other.

Negative correlationsAn association between increases in one variable and decreases in another.

Explaining correlationsCorrelations show patterns, not causes.Third variable effect or confounding variable: an alternative explanation for the cause of a behavior or event other than the expected causeCorrelational analysis can not rule out confounding variables.

Experimental Research Design Experiment: a controlled test of a hypothesis in which

the researcher manipulates one variable to discover its effect on another

Allows psychologists to determine the cause of a behavior by controlling for confounding variables

Example hypothesis: Using Lumosity daily for one week will improve performance on a memory test.

Research groups Experimental Group: exposed to

the variable of interest (treatment) These individuals will play

Lumosity games daily for one week, and then take a memory test.

Control Group: a comparison condition in which subjects are treated like the experimental group except for the variable of interest These individuals will play

Pacman games daily for one week, and then take a memory test.

Variables of interest

Independent variables Variables the experimenter manipulatesIV1: LumosityIV2: Pacman

Dependent variables Variables the experimenter predicts will be affected by manipulations of the independent variable(s)DV: Score on memory test

Age is not a true independent variable

Studies on aging are never true experiments because age can’t be manipulated. Studies on aging are never true experiments because age can’t be manipulated.

Quasi-experimental design allows researchers to compare groups on predetermined characteristics, including age, sex, ethnicity, and social class.

Some of APA’s ethical guidelines for research on

human participants

Research Methods:Observation

Researchers carefully and systematically observe and record behavior without interfering with behaviorNaturalistic observationPurpose is to observe how people or animals behave in their natural environments.Laboratory (Structured) observationPurpose is to observe how

people or animals behave

in a more controlled setting.

Research Methods:Daily Diary

Participants enter data on a daily basis such as personal ratings or activities.

Research Methods:Case report

A detailed description of a particular individual being studied or treated, which may be used to formulate broader research hypotheses

Research Methods:Archival Research

Uses existing resources containing data relevant to a question about aging.Example hypothesis: Young adult males have the highest rate of arrests.

Research Methods:Qualitative studies

Explores complex relationships in situations that don’t lend themselves to restrictions and assumptions of quantitative methods.

Example: How do you feel about the treatment of young

adult males by police?

Research Methods:Focus Groups

Meeting of respondents asked to provide feedback about a certain topic of interest.

Example: What services would you like to have on PCC’s campus?

Research Methods:Epidemiological Study

Study frequency of particular disease in the population. Example: How common is it to get breast cancer?

Designs for Studying Development

Cross-sectional designs: test or observe people of different ages at the same time.

Example: Researchers survey PCC students about their political opinions.

Designs for Studying Development

Longitudinal designs: test or observe the same individuals repeatedly at different points in their lives.

Example: Researchers follow a sample of individuals through their life to learn whether political opinions change over time.

Selective attrition: Loss of participation over time due to many factors, including: Illness Lack of motivation Instability Death Moving to a remote area

Designs for Studying Development

Sequential designs: represent different combinations of cross-sectional or longitudinal studies

Example: Researchers take a poll of PCC students at one point in time as well as follow a sample of individuals through their life to learn about political opinions and whether they change over time.

Designs for Studying Development

Meta-analysis: Integrates findings from different studies Powerful tool Determines whether a finding generalizes across many studies that used

different methods

• Reliability: Consistency in findings

• Validity: Does research measure the phenomenon of interest?

Research Methods