Chapter 2: Research Methods

SFU with Dr. Leavitt

What Makes Psychology a Science?

2.1 - 2.4

experience

personal events relating to a phenomenon

intuition

subjective feelings of what makes sense

intuition and experience have _______

limits

psychology _______ collects and _______ evidence across many people

systematically, averages

scientific method

process of basing one’s confidence in an idea of systematic, direct observations of the world, usually by testing ideas through research studies

theory-data cycle

process of scientific method where scientists collect data that can either confirm or deny a theory

what is the order of the theory-data cycle?

theory → research questions → research design → preregistration → data

theory

set of propositions explaining how and why people act, think or feel

hypothesis

specific prediction stating what will happen in a study if theory is correct

data

set of empirical observations scientists have gathered

replication

when a study is conducted more than once on a new sample of participants and obtains same basic results

more than _____ study is necessary to build confidence in a theory

one

results of psychological research are ________ and _________

peer-reviewed, made public

peer-review

other experts analyze study’s qualities and flaws

journal

periodical containing peer-reviewed articles on a specific academic discipline, written for a scholarly audience

variable

something of interest that varies from person to person, or situation to situation

what are the two types of variables?

measured and manipulated

measured variable

variable whose values are simply recorded (included in every study)

manipulated variable

variable whose values researcher controls, usually by assigning different participants different levels of the variable

some variables can only be ________

measured

operationalize

specific way of measuring or manipulating an abstract variable in a particular study

self-reporting

people describe themselves in an interview or survey, using a rating scale

direct observation

researchers observe and record the occurrence of behaviour (tech can be used to record physiological measures)

Three Kinds of Research

2.5 - 2.11

what are three types of research methods used to test theories?

descriptive, correlational, experimental

descriptive research

type of study where researchers measure one variable at a time with goal of describing what is typical

how is descriptive research often done?

surveys

how does survey research provide concise summaries of many people?

asking people to self-report

key terms in descriptive survey research

sample, population of interest, random sampling

sample

group who participated in research and belong to population of interest of researcher

population of interest

full set of cases researcher is interested in

random sampling

way of choosing sample of participants for a study where participants are selected without bias

observational research

descriptive research method where psychologists measure their variable of interest by observing/recording what people are doing

what are two kinds of observational research methods?

naturalistic, case study

naturalistic observation

observation research method where psychologists observe behaviour of animals or people in their regular worlds and environments

case study

observation research method where researchers study one or two individuals in depth, often with a unique condition

case studies do not _______ to a larger population but may offer insights and research inspiration

generalize

correlational research

type of study measuring two or more variables in the same sample of people, then observing the relationship between them

scatterplot

type of graph used to represent a correlation

each individual in a study is represented by a ___ in a scatterplot

dot

what are the types of correlations?

positive, negative, and zero

positive correlation

indicates high values of one variable are linked with high variables of the other

negative correlation

indicates high values of one variable are linked to low variables of the other

zero correlation

no systematic relationship between the two variables when observed and measured

perfect positive relationship

+1.00

no relationship

0.00

perfect negative relationship

-1.00

correlation is not _______, it is not enough to support casual claims

causation

three criteria must be met to conclude causation

• two variables must be correlated

• one variable must precede the other

• there must be no reasonable alternative explanations for the pattern of correlation

correlational can satisfy the _____ criterion only

first

correlations reveal ______, not enough to support casual claims

relationships

third-variable problem

an additional variable may be associated with both variables involved, making an alternative explanation for observed relationship

spurious correlations

accidental, meaningless correlations

experimental research

study where one variable is manipulated and its effect on one or more other variables is measured - can provide evidence on variables causes another

independent variable

manipulated variable in an experiment

dependent variable

measured variable in experiment

random assignment

procedure used in experimental research where a random method is used to decide which participants will receive each level of independent variable

there is a difference between random _____ and random ______

sampling, assignment

experimental (treatment) group

a group or condition where some proposed cause is present in an experiment

control (comparison) group

a group or condition where some proposed cause is not present in an experiment

placebo condition

group or condition where some people expect to receive a treatment but are exposed only to an inert version, such as a sugar pill

double-blind procedure

neither experimenters nor participants know who is in the experimental group or control group

how does double-blind procedure affect experiments?

reduces bias on behaviours/expectations

_________ is assured with the experimental method

temporal precedence

________ is established

correlation

good experiments can support casual claims by including these factors

independent variable, dependent variable, experimental group, control group

Identifying Good Research

2.12 - 2.15

validity

appropriateness/accuracy of a claim or conclusion

reliability

degree to which a measure yields consistent results each time it is admistered

what types of validity can research be evaluated on?

construct, external, and internal

construct validity

specific assessment of how accurately the operationalizations used in the study capture the variables on interest

external validity

degree to which it is reasonable to generalize from a study’s sample to its population of interest

external validity relies on what technique?

random sampling

internal validity

ability of a study to rule out alternative explanations for a relationship between two variables

confound

alternative explanation for a relationship between two variables, specifically when two experimental groups accidentally differ on more than just the independent variable

studies with confounds have poor ________

internal validity

how many main questions are there in the critical thinking toolkit for evaluating claims in popular media?

5

question 1: critical thinking toolkit

what am I being asked to believe?

question 2: critical thinking toolkit

what kind of evidence is there?

question 3: critical thinking toolkit

how strong is the result?

question 4: critical thinking toolkit

are they making a casual claim?

question 5: critical thinking toolkit

has the study been replicated?

_______ are used to understand draw conclusions about quantified, recorded behaviours

statistics

descriptive statistics

graph or computation describing characteristics of a batch of scores, such as its distribution, central tendency, or variability

frequency distribution

descriptive statistic that takes form of a bar graph

in frequency distribution, the x-axis represents __________ and is __________ on the y-axis

number of people who had each score / plotted

central tendency

identifies average or center of a batch of scores

key terms for central tendency

mean, median, and mode

mean

arithmetic average of a group of scores (added up and divided by # of participants)

median

middlemost score; obtained by lining up scores from smallest to largest and identifying middle score

mode

most common score in batch of scores

variability

extent to which scores in a batch differ from each other

standard deviation

variability statistic calculating how much, average, a batch of scores varies around its mean

____________ score indicates greater variability in a batch of scores

higher standard deviation

effect size

numerical estimate of strength between two variables; difference between two group means divided by standard deviation of the two groups

correlation coefficient

statistical measure that calculates strength and direction of a linear relationship between two variables

scatterplots indicate strength of association between variables by how _________ the dots are

spread apart

when dots are spread out, there is a ______ effect size

weaker

direction of correlation

slope