Dr. Feria Exam III Study Guide

external validity

external validity

extent to which the results of the study can be generalized to other people, setting, conditions, and measures

threats to external validity

generalizations of other people, generalizations of different measures/operational definitions, generalization to different settings

volunteer bias

when volunteers aren't representative of the general population

replication

repeating conceptually similar testing hypothesis

exact replication

repeat precisely the same procedures to see whiter the same results are obtained

conceptual replication

using different procedures to replicated a finding; use same IV and DV but different operations definition, aka some aspects changed

internal validity

ability to say that independent variable caused a difference in dependent variable

extraneous variable

any variable in a research study other than specific variables being studied; ex. IQ, sleep amount, how food eaten beforehand, etc.

threats to internal validity

confound, experimental bias, random error

how to avoid experimenter bias

double blind study, create a script, computerize study, make DV objective (not up for interpretation) , don't let anyone know the hypothesis

confounds

extraneous variable that changes along with IV

random error

inconsistent increases and decreases in individual's score

confound vs. random error

in confound, extraneous variable makes it look like there is a difference between conditions. In random error extraneous variable creates random increases and decreases in individual score

double blind experiment

both participant and experimenter don't know the group's conditions

demand characteristics

participants figure out what the researcher is looking for, and then do "what's expected"

example of demand characteristic

if participants are given alcohol and a reading comprehension test, they'll figure out that they're expected to do worse

assignment bias

when participants in the conditions have different characteristics and aren't randomly assigned to each condition.

existing groups

example of existing groups

smokers in the engineering division of the company receives treatment but smokers from the marketing division don't.

order of availability

put people in each condition based on when they are available

example of order of availability

people who sign up for a study early in the semester vs. students who sign up later may have different personality types, motivation differences, organization skills, etc.

handling threats to validity

1. control extraneous variables (as much as possible)

2. distribute bias across conditions

trade off between internal and external validity

having better internal validity will mean that it may be better control over the factors vs. better external validity where it can be applied to real life more

nazi medical experiments

during WWII, Nazi doctors would conduct unethical experiments on their prisoners. This lead to the creation of the Nuremberg Code (1947), where the whole world got together to try and prevent these unethical experiments from happening again. Not enforced though

Institutional Review Board (IRB)

committee that must look over and approve research before it can start (for human subjects)

protocol

research proposal

presence/absence variable

variable involves a manipulation with two levels; one level that involves the treatment and the other that does not involve treatment

Presence/absence variable example

type variable

a variable that involves manipulation of the types of a treatment; a different type of "something" being compared to the DV

type variable example

different types of drugs and therapies can be compared on a depression questionnaire to see the effectiveness of each one

amount variable

variable that includes levels with a different amount of the treatment changing from level to level

single-bind design

procedure used to hide the group assignment from the participants in a study to prevent their beliefs about the effectiveness of a treatment from affecting the results

regression towards the mean

can occur when participants score higher or lower than their personal average—the next time they are more likely to score near their personal average, making scores unreliable

field experiment

an experiment conducted in the participants' natural environment

Nazi Medical experiments

nazis did unethical experiments on their prisoners to learn about the limits to the body and mind when exposed to extreme temperatures, infections, and chemicals

Institutional Review Board (IRB)

committee that must look over and approve research of human subjects before it can be started

office for Human Research Protections (OHRP)

office of federal government that oversees human subjects research all over the U.S. Has the power to shut down an entire human research program if any extreme outcomes occur (ex. death)

confidentiality

scientists must not report data of a personal mature to other scientists or groups without participants consent

anonymity

personal identification of given participant is kept separate

risk/benefit ratio

the balance of risk and benefit of an experiment; does the benefit outweigh the risk?

voluntary participation

participants chose to do the study by their own free will

Tuskegee Syphilis Study

African American men with Syphilis, but didn't know, were part of a study (that wasn't consensual) where the researchers wanted to see how long of a life these men can live with this disease. They weren't given treatment even when it became available

coercion

anything that makes it hard for a person to say "no"; ex. large money compensation

informed consent

consent obtained by participants to take part on the study after being made aware of the risks, purpose, and procedure

special populations

some people don't have the ability to make a free and informed decision to participate, thus needing special protection; ex. children under 6, disabled people, patients, etc.

deception

active misrepresentation of information

withholding information

it's necessary to withhold: hypothesis and which conditions participants are in. Don't withhold: anything that can affect decisions to participate (ex. risks)

debriefing

explanation of purposed of the research that is given to participants after study

Nuremberg Code

created after WWII as a way to prevent what happened during the Nazi experiments to repeat itself. 4 guidelines:

1. must be voluntary. Include information necessary for participant to continue with the study (I.e. risks) 2.must contribute to scientific knowledge and be conducted by qualified researchers

2. researchers must avoid unnecessary harm, take precautions, benefit must outweigh risk, and end study if becomes out of control

3. give participants the right to end study if they feel is necessary