chapter 2: methods in psychology

hindsight bias

tendency to believe, after learning an outcome, that we could have predicted it

overconfidence bias

people tend to think they know more than they do

tendency to perceive patterns in random events

people trust their intuition more than they should because intuitive thinking is flawed

empiricism

relying on observation, experimentation, or measurement.

observe

use one’s senses to learn about the properties of an event or an object

Limitations:

• inconsistent

• incomplete

hypothesis

testable prediction, often implied by a theory

• precise, clearly worded statements that describe what researchers think  may be true. often If/ then statements.

replication

repeating the essence of a research study

basic research

pure science that aims to increase knowledge base

ex: find out the current state of wellness among high school students, specifically LHS

applied research

scientific study that aims to influence practical problem

ex: present Mr.Baker with recommendations  of how LHS can increase happiness & reduce student stress

operational definitions

a carefully worded statement of a property or procedure so others can replicate the study

[happiness is measured by the General Happiness score]

construct validity

extent to which the thing being measured adequately characterizes the property [happiness scale]

ex: does operational definition help characterize what we’re looking for

reliability

examination of how consistent and stable the results of an assessment are

inter-rater reliability

degree to which different raters give consistent estimates of the same behavior

ex: if many people were able to count the same number of smiles

duchenne smile

long & intense through the contraction of 2 muscles. tugs at the corner of your mouth & around your “twinkling eyes”

demand characteristics

 a subtle cue that makes participants aware of what the experimenter expects to find or how participants are expected to behave.

hawthorne effect

people will modify their behavior simply because they are being observed

observer bias

researchers expectations influence what they are observing

self fulfilling prophecy

high expectations lead to better performance and low expectations lead to worse - rosenthal study

double-blind study

neither the researcher not participant know what is be observed/measured

reduce demand characteristics & observer bias

descriptive research design

purpose: describes behaviors

how conducted: case studies, surveys, or naturalistic observations

what is manipulated: nothing

weaknesses: no control of variables, single cases may be misleading

correlational research study

purpose: to detect naturally occurring relationships, to assess how well one variable predicts another

how conducted: compute statistical association, sometimes among survey responses

what is manipulated: nothing

weaknesses: does not specify cause and effect

experimental research study

purpose: manipulates variables to explore cause and effect

how conducted: manipulate one or more factors, use random assignment

what is manipulated: independent variable(s)

weaknesses: sometimes not feasible; results may not generalize to other contexts; not ethical to manipulate certain variables

descriptive research

used to define and describe behaviors or trait, may reveal relationships but is not causal. it is typically the first step in research.

case study/method

examines one individual in depth

cannot be used to generalize, does not explain behavior

naturalistic observations

records behavior in natural environment

great in early stages of research

can be revealing but does not explain behavior

surveys and interviews

Q’s that ask about past behaviors, personal attitudes, and beliefs.

random sample (fairly represents a population) to avoid a sampling bias

correlation

shows the relationship of 2 variables → predicts the possibility of cause and effect relationships but cannot prove them. 

r can range from -1 to +1

confounding variable

occurs when an observed correlation between two variables can actually be explained by a third variable that hasn't been accounted for

illusory correlation

refers to the perception of a relationship between two variables when only a minor or no relationship actually exists ex. superstitions

regression toward the mean

refers to the tendency for extreme or unusual scores or events to fall back toward the average

→ suggest that when evaluating a situation, we must rely on the average rather than the outliers.

cross sectional study

study people of different groups (cohorts) at the same point in time → cohorts can be based on age, gender, income, etc.

data can come from surveys

advantages: inexpensive, can be completed quickly

disadvantages: different age groups are not necessarily much alike, differences may be due to between group differences not cohorts

longitudinal study

study the same group of people (cohort) over time

• data is first collected at the outset of the study, and may then be repeatedly gathered throughout the length of the study.

advantages: detailed information about subjects, developmental changes tracked over time

disadvantages: expensive, time consuming, high attrition (ppl. leaving)

quantitative methods

ask "what" and "how much"  numerical

methods:  experiments, correlational studies

qualitative methods

ask "why" and "how"

methods:  interviews, observations

frequency distribution

graphic representation showing the # of times the property takes on each of its possible values

normal curve (normal distribution)

symmetrical, bell-shaped curve that describes the distribution of many types of data; (about 68 percent fall within one standard deviation of it) and fewer and fewer near the extremes.

measure of central tendency

points the researcher toward a centralized, repeated, or average number

drawback: a few extreme scores can distort the data.

mean, median, mode

experiment involves

• manipulating independent variables

• randomly assigning participants to groups

• measuring dependent variables

• 1. manipulate a variable- identify independent variable (condition that is introduced to the experimental group). Control group does not get the IV.

• 2. measure the variable. did you see effect on some behavior or mental process? that is your dependent variable. 

• 3. compare the control group to the control group to the experimental group

random sampling

everyone in the entire target population has an equal chance of being selected

random assignment

each participant has an equal chance of being assigned to the independent variable

inferential statistics

drawing conclusions about a sample population to make generalizations about whole population.

null hypothesis

no relationship between the variables → trying to prove wrong

statistical significance

when sample averages are reliable and difference between them is relatively large

proof beyond reasonable doubt

odds of its occurrence by chance are less than 5 percent.  p (probability) <.05

ethics codes

• Informed consent must be given, and participation must be voluntary.

• Students may not be coerced into research participation.

• Deception can be employed only under certain conditions.

• Personal information about research participants must remain confidential.

• Information about the study must be provided to participants, who should also be debriefed.

participants cannot be placed at significant mental or physical risk. this clause requires interpretation by the IRB

nonhuman animals in research

• about 7-8% of psychological research use animal

  • 90% of the animals used have been rodents and birds, principally rats, mice, and pigeons. only about 5% of the animals are monkeys and other primates

• why? humans share common ancestry with the species most commonly studied in psychology: mice, rats, monkeys.

• animal research may involve certain harms that can range from the relatively minor (e.g., drawing a blood sample) to the more serious (e.g., neurosurgery). 

• animal research is tightly regulated on a local, state and federal level