PSY100: Ch 2, Research methods

Theory

set of facts and relationships between facts that can explain and predict related phenomena

Hypothesis

proposed explanation for a situation usually under the form 'if A happens, then B will be the result' ( type of inference/educated guess based on prior evidence and logical possibilities)

surveys

a descriptive method in which participants are asked the same questions

replication

repeating an experiment and producing the same results

case study

in-depth analysis of the behaviour of one person or a small number of people

double blind procedure

research in which neither the observer nor the subjects know which subjects received which treatment

normal distribution

bell-shaped curve of scores with a large number in the middle and very few on the high and low ends

naturalistic observation

research method based on the careful recording of behaviour in normal settings

dependent variable

element of the experiment that measures any effect of the manipulation

experiment

studies in which the investigator manipulates at least one variable while measuring at least one other variable

correlational research

non experimental study that quantifies the degree to which events, measures or variables are associated

reliability

stability of test scores over time

descriptive statistics

mathematical summaries of results such as measures of the average and amount of variation

inferential statistics

mathematical method for extending experimental conclusions from samples to larger populations

control group

subjects in an experimental study who do not receive the treatment being investigated

correlational coefficient

statistical index ranging from -1.00 to +1.00 that indicated how strongly a pair of variables are associated

placebo effect

change in symptoms due to a participant's expectation that a drug or treatment will do something

placebo

inactive substance or treatment that cannot be distinguished from a real active substance or treatment

sample

subset of a population being studied

independent variable

experimental variable controlled and manipulated by the experimenter, "if A happens part of a hypothesis

experimental group

group of participants who are exposed to the independent variable

random assignment

procedure in which participants have an equal chance of being placed in any group in an experiment

• keeps internal validity of the experiment

confounding variables

variable that is irrelevant to the hypothesis being tested but can alter the researchers conclusions

meta-analysis

statistical analysis of many previous experiments on a single topic

publication bias

possibility that published studies are not representative of all work done on a particular phenomenon

cross-sectional study

experiment designed for assessing age-related changes in which data are obtained simultaneously from people differing ages

longitudinal study

assesses age-related changes in which data are obtained from the same individuals over a long period of time

validity

quality of a measure that leads to correct conclusions (the measure that evaluates the concept it was designed to do)

mean

numerical average of a set of scores

median

halfway mark in a data set with half of the scores above it and half of the scores below it

mode

most frequently occurring score in a data set

standard deviation

measure of how tightly clustered around the mean a group of scores is

statistical significance

standard for deciding whether an observed result is because of chance

Confirmation bias

the tendency to notice and remember instances that support your beliefs more than instances that contradict them

construct

internal attributes or characteristics that cannot be directly observed but are useful for describing and explaining behaviour

operational definition

definitions of theoretical constructs that are stated in term of concrete, observable procedures

• Variables can be well-defined and easily measured or manipulated
• Some variables are not well-defined and cannot be directly observed

descriptive research

often concerned with a single variable of interest. Involves the systematic observation and classification of behaviour. Provides qualitative information (surveys, focus groups, case studies, observational research)

directionality problem

there are multiple possibilities that could explain the association between variables and the test does not tell us which one is correct

third variable problem

there could be a 3rd variable that is not considered that is actually responsible for the results of the experiment

external validity

generalizability

internal validity

how well the study has established a cause and effect relationship

WEIRD samples

Western, Educated, Industrialized, Rich, and Democratic

• populations are generally favoured for experiments, not fully representing the general public 

open science

• movement to make scientific research accessible to all levels of society, amateur or professional
• transparent and accessible knowledge that is shared and developed through collaborative networks.

Hawthorne effect

alteration of behaviour by the subjects of a study due to awareness of being observed

• limitation of descriptive research methods
• demand characteristics

quasi experiments

experimental design where random assignment is not possible

• potential confounds limits researcher claims
• taking advantage of pre existing groups

interrater reliability

measure of consistency used to evaluate the extent to which different judges agree in their assessment decisions

test-retest reliability

a measure of reliability obtained by administering the same test twice over a period of time to a group of individuals