unit 0 (psycholgical science practices)

Includes: Non-Experimental Methods, the Experiment, Ethical Guidelines, and Statistical Interpretations

hindsight bias

the tendency to believe, after learning an outcome, that one would have forseen it

overconfidence

the belief that one knows more than one actually does (most factual questions are given more confident answers than correct)

perceiving order in random events

the ability to find patterns in random data to create predicability in our world

critical thinking

a way of thinking that doesn’t automatically accept arguments and conclusions

theory

explains behaviors and events by offering ideas that organize observations

hypothesis

a testable prediction produced by a theory

operational defintion

a precise statement of the exact procedures used in a research study

non-experimental methods

methods of psychology that utilize observations and descriptions, rather than a controlled/manipulated environment

case study

an indepth analysis of a certain individual or groups in hopes of revealing universal principles

strengths of a case study

• allows the investigators to directly observe the subject in a natural setting (especially in animal case studies)

• often useful in the first stages of a research program

limitations of a case study

• allows researchers little to no control of the situation

• observations may be biased

• doesn’t allow for a firm conclusion of a cause and effect

naturalistic observation

the recording of the natural behavior of individuals without trying to manipulate and control the situation

observer effect

the tendency of people to behave different when they know they are being watched

hawthorne effect

the tendency of individuals to improve their performance or behavior because they are aware that they’re a part of an experiment or study

observer bias

also called, “research bias”

the tendency to unconciously see or interpret behaviors that align with their expectations, and possibly interpreting unclear or uncertain results in favor of the researcher

strengths of a naturalistic observation

• allows the investigator to directly observe the subject in a natural setting

• often useful in the first stages of a research program

weaknesses of a naturalistic observation

• allows little to no control of the situation

• observations may be biased

• doesn’t allow firm conclusions

survey

a method of study that involves asking people questions and consequently reporting their behavior or opinion

sampling bias

a flawed sampling process, which produces an unrepresentative sample

random sample

a randomly selected sample of the population being studied, specifically used in surveys

meta-analysis

a statistical technique that combines the results of multilpe studies, addressing a common research question to produce an overall more reliable effect (a study on studies)

correlational study

a measurement of the relationship between two or more variables, and the strength of the relationship between the variables

positive correlation

when one variable increases so does the other (and vice versa), and when one variable decreases so does the other (and vice versa)

negative correlation

when one variable decreases the other increases (and vice versa)

correlation coefficient

defined as, “r”

the closer to -1 or 1 the coefficient is, the stronger the relationship is between the 2 variables

spurious correlation

when there’s a statistical corrleation between variables, but the correlation is a coincidence and there is no real relationship between the variables

directionality problem in correlational research

the lack of cause and effect information: researchers don’t know if [x] causes [y], or if [y] causes [x]

third-variable problem in correlational research

the possibility, which researchers cannot rule out, that a third variable causes either or both of the variables to increase/decrease

illusory correlation

the mistaken perceivance of a relationship between two variables or events that are unrelated, typically when two unrelated events occur together

regression toward the mean

the tendency for extreme or unusual scores or events to regress toward the average

experiment

a research method that involves the researcher to manipulate one or more variables in order to observe the effect on a behavior or mental process

independent variable

the factor that is manipulated, or the variable whose effect is being studied

dependent variable

the variable whose outcome is being measured in a specific manner, or the variable that is being observed to evaluate the effects of the independent variable

confounding variable

a factor that could influence a study’s results; researchers attempt to identify and control this variable to minimize its effect

experimental group

the group exposed to a changed independent variable (one specific version of it)

control group

the group not exposed to a changed independent variable, and serves as a comparison for the experimental group to evaluate the effects of the independent variable

random assignment

the assignment of participants to specific experimental and control groups by chance, and thus minimizing pre-existing differences between the groups

strengths of the experiment

• allows for researchers to identify a cause-and-effect relationship between two correlated variables

• if the experiment is reliable, researchers can develop a firm conclusion

limitations of the experiment

• creates a contrived situation, and the more contrived a situation is the more artifical behaviors become

• ethical concerns on how certain experiments should be carried out

• perceived effects and biases that affect the actual results of the experiment

single-blind procedure

the participants are uninformed about what treatment they may be receiving, but the researchers do have knowledge as to who is in what group

double-blind procedure

a method in which neither the participants nor those who are administering the drug and collecting the data will know which group is receiving a treatment

placebo effect

an effect that greatly affects experimental results as it produces effects just by expectations alone; for example, thinking that you are getting a treatment can relieve your symptoms due to the placebo effect

American Psychological Association (APA) Guidlines

A set of ethical guidelines that state that researchers must provide “humane care and healthful conditions” and that testing should “minimize discomfort”

informed consent

an ethical standard for researchers which gives potential participants enough information about a study to enable them to choose whether they wish to participate

debrief

an post-experimental explanation of a study, including its purpose and any deceptions, to its participants

descriptive statistics

numerical data used to measure and describe characterics of groups; includes measures of central tendency and measure of variation

measures of central tendency

a single score that represents a whole set of scores

mode

the most frequently occuring score(s)

mean

the arithmetic average: the total sum of all the scores divided by the number of scores

median

the midpoint of a data distribution

percentile rank

the percentage of scores that are less than a given score

standard deviation

a computed measure of how much scores vary around the mean score

normal curve

a symmetrical, bell-shaped curve that describes the distribution of many types of data (most scores fall near the mean)

negative skew

a situation where the curve has a tail towards the lower values on the graph

positive skew

a situation where the curve has a tail towards the high values on the graph

inferential statistics

the use of numerical data to generalize and infer the probability of something being true of a population similar to the sample data

null hypothesis

the assumption that no difference exists between the groups

alternative hypothesis

a hypothesis that supports the notion that there is a difference between the control and experimental groups

p-value

the probability of the result, if the null hypothesis were to be true

statistically significant

a term used to describe a result with a very low p value (p < 0.05), which leads to the rejection of the null hypothesis and the acceptance of the alternative hypothesis

effect size

the strength of the relationship between two variables; the larger the effect size, the more one variable can be explained by the other