Chapter 2 - Research Methodology

Critical Thinking

Systemically evaluating information to reach reasonable conclusions

Amiable Skepticism

Open to new ideas, but wary of new findings if not supported by scientific evidence and sound reasoning

Objectivity

Makes a source credible

Empirical

Based on scientific investigation. Counts as evidence

Scientific Consensus

When empirical research suggests a single conclusion

Scientific Inquiry

Empirical questions about the what, when, why, and how of behavior and mental processes

Scientific Method

Systematic procedure for observing & measuring phenomena to answer empirical questions. Goal is to be bias-free

Theory

An explanation or model of what gives rise to phenomenon. It’s one of the three critical elements of the scientific method

Hypothesis

A specific, testable prediction about the study outcome that would best support the theory. It’s one of the three critical elements of the scientific method

Research

The systematic and careful collection of data, and their quantitative analysis. It’s one of the three critical elements of the scientific method

HOMER

Hypothesize, Operationalize, Measure, Evaluate, Repliacate/Revise/Report

Variable

Something in the world that can vary (or can be manipulated) & that a researcher can measure

Operational definition

Identifying and quantifying variables so they can be measured

Population

Everyone in the group the experimenter is interested in

Sample

A subset of a population. Should be representative of the population and unbiased

Random Sampling

Everyone in the population has an equal chance of being chosen to participate

Convenience Sampling

Using participants who are available to you. May not be a representative sample for some questions

Descriptive Studies

Involve observing & noting the behavior of people or other animals to provide a systematic & objective analysis of the behavior

Naturalistic Observation

Passive observation; don’t interact in situation. Type of descriptive study

Participant Observation

Active involvement; involved in situation. Type of descriptive study

Observer Bias

Systematic errors in observation that occur because of an observer’s expectations. One of the caveats of descriptive study

Experimenter expectancy effect

Actual change in the behavior of people/animals observed due to expectations of the observer or due to observation. One of the caveats of descriptive study

Correlational Studies

Examines how variables are naturally related in the real world, without any attempt by the researcher to alter them

Directionality Problem

Researchers find a relationship between two variables but cannot determine which variable may have caused changes in the other variable. One of the caveats of correlational study

Third variable problem

Researchers cannot be confident that an unmeasured variable is not the actual cause of the effects in the variables of interest. One of the caveats of correlational study

Experimental Studies

Study that tests casual hypotheses by measuring and manipulating variables. Hypothesis is factor X causes factor Y

Independent Variable

The variable that changes in the experiment and doesn’t depend on another. Should be the only difference between conditions in an experiment

Dependent Variable

The variable to changes due to the independent variable. Gives you the result of an experiment

Confounding Variable

Anything that affects the DV and may unintentionally also vary between experimental groups of a study. Provides an alternative explanation for the results

Selection Bias

Unintended differences between participants in different groups

Random Assignment

Each participant has an equal chance of being assigned to any level of the IV, to ensure preexisting differences are randomly distributed between groups. Happens DURING the experiment, NOT before

Cons of Experimental Study

May be labor-intensive/costly; often take place in artificial settings; samples may not generalize to population

Data

Objective observations or measurements; tests the hypothesis. Can come from observation, case studies, self report, response performance, body-brain activity

Validity

Extent to which study actually measures what it intends to measure

Reliability

Extent to which a measure is stable and consistent over time (or across replications by others)

Internal validity

The degree to which the effects observed in an experiment are truly due to the manipulation of the independent variable

External Validity

The degree to which the findings of a study can generalize to the real world

Descriptive Statistics

Characterize the group of data collected in a study

Central tendency

Describes a typical response or behavior of a group as a whole. Doesn’t apply to everyone, but doesn’t negate the research finding

Mean

Average of a set of numbers (shortest distance to all datapoints)

Median

The value in a set of numbers that falls exactly halfway between the upper and lower halves of the datapoints

Mode

The most frequent datapoint in a set of numbers

Variability

How widely dispersed the values are from each other and the mean

Standard Deviation

How far away each value is, on average, from the average. Usually reflects percent of population

Positive Correlation

Both variables increase or decrease together

Negative correlation

As one variable increases, the other decreases

Inferential Statistics

Set of procedures used to make inferences about whether differences actually exist between sets of data (aka reach a conclusion based on results)

Statistically significant result

Differences not likely due to chance. Generally psych uses (p<.05), or 5% chance, as a significance level