Experimental Psychology

*Prediction* it is the outcome the researcher expects to observe if the theory accurate.

Hypothesis

variable that is manipulated

independent variable

levels are coded with meaningful number a long continuum

Quatitative

(2) variable claim argues that one level of a variable is likely to be associated with a particular level of another variable

association claim

Set of statements that describes general principles about how variables relate to one another.

Theory

Scientists test theories through research and then adapt their theories accordingly.

Theory Data Cycle

theory, research questions, research design, hypothesis, data

Theory-Data Cycle (steps)

When institutional approval is required, psychologists provide accurate information about their research proposals and obtain approval prior to conducting the research. They conduct the research in accordance with the approved research protocol.

8.01 Institutional Approval

Can be measured or manipulated

2 Characteristics of variables

Self-report Measures Observational Measures Physiological Measures

3 common types of Meausres

self-report, observational, physiological

3 common types of measures

covariance, temporal precedence, internal validity

3 criteria for causation

1) construct 2) external 3) internal 4) statistical

4 types of validity

(a) When obtaining informed consent as required in Standard 3.10, Informed Consent, psychologists inform participants about (1) the purpose of the research, expected duration, and procedures; (2) their right to decline to participate and to withdraw from the research once participation has begun; (3) the foreseeable consequences of declining or withdrawing; (4) reasonably foreseeable factors that may be expected to influence their willingness to participate such as potential risks, discomfort, or adverse effects; (5) any prospective research benefits; (6) limits of confidentiality; (7) incentives for participation; and (8) whom to contact for questions about the research and research participants' rights. They provide opportunity for the prospective participants to ask questions and receive answers. (See also Standards 8.03, Informed Consent for Recording Voices and Images in Research; 8.05, Dispensing with Informed Consent for Research; and 8.07, Deception in Research.) (b) Psychologists conducting intervention research involving the use of experimental treatments clarify to participants at the outset of the research (1) the experimental nature of the treatment; (2) the services that will or will not be available to the control group(s) if appropriate; (3) the means by which assignment to treatment and control groups will be made; (4) available treatment alternatives if an individual does not wish to participate in the research or wishes to withdraw once a study has begun; and (5) compensation for or monetary costs of participating including, if appropriate, whether reimbursement from the participant or a third-party payor will be sought. (See also Standard 8.02a, Informed Consent to Research.)

8.02 Informed Consent to Research

psychologist obtain informed consent prior to recording their voices or images for data collection unless (1) research is naturalistic, not gonna cause personal identification or harm (2) uses deception and consent for use of recording is obtained during debriefing

8.03 Informed Consent for Recording Voices and Images in Research

(a) must protect participants from adverse consequences of declining or withdrawing from participation (b) when research participation is for extra credit the participant is given the choice of equitable alternative activities

8.04 Client/Patient, Student, and Subordinate Research Participants

Psychologists may dispense with informed consent only (1) where research would not reasonably be assumed to create distress or harm and involves (a) the study of normal educational practices, curricula, or classroom management methods conducted in educational settings; (b) only anonymous questionnaires, naturalistic observations or archival research for which disclosure of responses would not place participants at risk of criminal or civil liability or damage their financial standing, employability or reputation, and confidentiality is protected; or (c) the study of factors related to job or organization effectiveness conducted in organizational settings for which there is no risk to participants' employability, and confidentiality is protected or (2) where otherwise permitted by law or federal or institutional regulations.

8.05 Dispensing with Informed Consent for Research

(a) psychologist make reasonable efforts to avoid offering excessive or inappropriate financial or other inducements as coercion (b) when offering professional services as an inducement, psychologist must clarify the nature of the services, risks, obligations, limitations

8.06 Offering Inducements for Research Participation

(a) Psychologists do not conduct a study involving deception unless they have determined that the use of deceptive techniques is justified by the study's significant prospective scientific, educational, or applied value and that effective nondeceptive alternative procedures are not feasible. (b) Psychologists do not deceive prospective participants about research that is reasonably expected to cause physical pain or severe emotional distress. (c) Psychologists explain any deception that is an integral feature of the design and conduct of an experiment to participants as early as is feasible, preferably at the conclusion of their participation, but no later than at the conclusion of the data collection, and permit participants to withdraw their data. (See also Standard 8.08, Debriefing.)

8.07 Deception in Research

(a) Psychologists provide a prompt opportunity for participants to obtain appropriate information about the nature, results, and conclusions of the research, and they take reasonable steps to correct any misconceptions that participants may have of which the psychologists are aware. (b) If scientific or humane values justify delaying or withholding this information, psychologists take reasonable measures to reduce the risk of harm. (c) When psychologists become aware that research procedures have harmed a participant, they take reasonable steps to minimize the harm.

8.08 Debriefing

(a) Psychologists acquire, care for, use, and dispose of animals in compliance with current federal, state and local laws and regulations, and with professional standards. (b) Psychologists trained in research methods and experienced in the care of laboratory animals supervise all procedures involving animals and are responsible for ensuring appropriate consideration of their comfort, health and humane treatment. (c) Psychologists ensure that all individuals under their supervision who are using animals have received instruction in research methods and in the care, maintenance and handling of the species being used, to the extent appropriate to their role. (d) Psychologists make reasonable efforts to minimize the discomfort, infection, illness and pain of animal subjects. (e) Psychologists use a procedure subjecting animals to pain, stress or privation only when an alternative procedure is unavailable and the goal is justified by its prospective scientific, educational or applied value. (f) Psychologists perform surgical procedures under appropriate anesthesia and follow techniques to avoid infection and minimize pain during and after surgery. (g) When it is appropriate that an animal's life be terminated, psychologists proceed rapidly, with an effort to minimize pain and in accordance with accepted procedures.

8.09 Humane Care and Use of Animals in Research

(a) Psychologists do not fabricate data. (b) If psychologists discover significant errors in their published data, they take reasonable steps to correct such errors in a correction, retraction, erratum or other appropriate publication means.

8.10 Reporting Research Results

Psychologists do not present portions of another's work or data as their own, even if the other work or data source is cited occasionally.

8.11 Plagiarism

(a) Psychologists take responsibility and credit, including authorship credit, only for work they have actually performed or to which they have substantially contributed. (See also Standard 8.12b, Publication Credit.) (b) Principal authorship and other publication credits accurately reflect the relative scientific or professional contributions of the individuals involved, regardless of their relative status. Mere possession of an institutional position, such as department chair, does not justify authorship credit. Minor contributions to the research or to the writing for publications are acknowledged appropriately, such as in footnotes or in an introductory statement. (c) Except under exceptional circumstances, a student is listed as principal author on any multiple-authored article that is substantially based on the student's doctoral dissertation. Faculty advisors discuss publication credit with students as early as feasible and throughout the research and publication process as appropriate

8.12 Publication Credit

Psychologists do not publish, as original data, data that have been previously published. This does not preclude republishing data when they are accompanied by proper acknowledgment.

8.13 Duplicate Publication of Data

(a) After research results are published, psychologists do not withhold the data on which their conclusions are based from other competent professionals who seek to verify the substantive claims through reanalysis and who intend to use such data only for that purpose, provided that the confidentiality of the participants can be protected and unless legal rights concerning proprietary data preclude their release. This does not preclude psychologists from requiring that such individuals or groups be responsible for costs associated with the provision of such information. (b) Psychologists who request data from other psychologists to verify the substantive claims through reanalysis may use shared data only for the declared purpose. Requesting psychologists obtain prior written agreement for all other uses of the data.

8.14 Sharing Research Data for Verification

Both variables.

Association claims must be assessed for _____________.

estimating the likelihood of events based on their availability in memory; if instances come readily to mind (perhaps because of their vividness), we presume such events are common

Availability heuristic

Assessed for both the Independent variables and dependent variables

Causal Claims: Construct Validity

a claim arguing that a specific change in one variable is responsible for influencing the value of another variable

Causal claims

Does the causal finding generate to the population, other populations, other contexts?

Causal claims: External validity

How strong is the association? Effect size? Is the relationship/association due to chance? Statistically significant?

Causal claims: Statistical validity

based on correlations of scores on one meausre of those of a RELATED measure (administered concurrently)

Concurrent validity

the tendency to ask only the questions that will lead to the expected answer

Confirmatory hypothesis testing

No cause/ effect

Confounds

Criterion validity, Convergent validity, Discriminant validity

Construct validity: Empirical

Face Validity and Content Validity

Construct validity: Subjective

variables are often expressed in abstract terms

Constructs

Distracting group

Control Group

variables are related to each other. As "A" changes, "B" changes

Covariance

computes the average correlation among all the items in the test. Best way to assess internal reliability with larger surveys

Cronbach's alpha

set of observations that may support or challenge the theory, depending on whether they are consistent with hypothesis

Data

.00 to .59: very low, peer reliability .60 to .69: low or peer reliability .70 to .79 moderate, fair reliability....... etc.

Descriptive Indices or Reliability

asks whether the operational definition correlates with measures dissimilar concepts. The construct should not correlate with measure that are conceptually very different

Discriminant validity

Low unknown but potentially meaningful sources of error; not stable across time/situation.

Essential in psychological measures

Celsius temperature scale, calendar time.

Example of Interval

one variable is manipulated and the other is measured.

Experiment

test length: more items --> greater likelihood of higher interval consistency guessing- lower reliability

Factors Affecting Reliability

1) Supported by data 2) Falsifiable--> alternative hypothesis 3)Parsimony

Features of good scientific theories

describe a particular rate or degree of a SINGLE variable

Frequency claims

How well a conceptual variable is operationalized??

Frequency claims: construct validity

how well the results of a study generalize to, or represent, people or contexts besides those in the study itself

Frequency claims: external validity

the extent to which the study's statistical conclusions are accurate and reasonable

Frequency: Statistical validity

Scientists are empiricists

How do scientists approach their work?

Personal Experience, Intuition, Authority, Empirical Research

How do you generate an answer to questions?

Measure validity and measure reliability

How do you study operationalizations are good ones?

focuses on whether two individuals use operational definition in the same way

Inter-rater reliability

in order to support (or undermine) a theory, scientists must make claims about the data they gather

Interpreting information

order with interval values (.25, .26); no actual zero

Interval variables

Objective Easy to replicate Reliable

Many possible operational definitions for any conceptual variables

interval variables that have a zero starting point.

Ratio Variables

how consistent the results of a measure are

Reliability

time. raters. content.

Reproducibility

operationalizes a variable by recording people's answers to questions about themselves in a questionnaire or interview

Self-report measures

observations are structured so that they can speak directly to the issue being evaluated

Systematic

based on observation or experiment

empirical

Face validity Content validity Criterion validity Convergent validity Discriminant validity

There are five types of evidence that help our case (construct validity):

True

True or False Not every test is expected to have high high test-retest reliability

ordinal, interval, ratio

Types of Quantitative Variables

frequency claims, association claims, causal claims

Types of claims

something that varies

Variable

cognitive short-cuts (rules of thumb)

We rely on _______________ to evaluate evidence: intuition is biased

If two theories explain the data equally well, the simplest solutions is the best. Least complex.

What is parsimony?

Objective Easy to replicate Reliable

What makes a good operational definition?

Convergent; Divergent

__________ and ____________ validity assess if the operational definition produces results that are consistent with other related measurements.

one that has two or more categories, but there is no intrinsic ordering to the categories. For example, gender is a categorical variable having two categories (male and female) and there is no intrinsic ordering to the categories. Hair color is also a categorical variable having a number of categories (blonde, brown, brunette, red, etc.) and again, there is no agreed way to order these from highest to lowest.

categorical nominal

Individuals create their own "subjective social reality" from their perception of the input.

cognitive bias

based on correlations of scores on one measure with those of a related measure

concurrent validity

"when people would like a certain concept/idea to be true end up believing it to be true." We attend to evidence that confirms our beliefs, but ignore evidence that contradicts them

confirmation bias

asks whether the operational definition correlates with measures of similar concepts

convergent validity

Criterion should be readily measurable, reliable, and relevant to the purposes of the test.

criterion-related validity

measured variable

dependent variable

Weight or height

example of ratio data

supported by data, falsifiable, have parsimony

features of good scientific theories

focuses on whether people give consistent responses to the test

internal reliability

a study should be able to eliminate alternative explanations for the association

internal validity

an amount (usually small) that is allowed for in case of miscalculation or change of circumstances. Frequency of distribution calculates

margin of error

utilize clearly defined methods that allow others to collect and evaluate the same data

objective

operationalizes a variable by recording observable behaviors or physical traces of behaviors

observational measures

concrete description of how a variable is to be measured in a particular study

operational definition

As in rankings like 1st place, 2nd place etc.

ordinal variables (categorical)

operationalizes a variable by recording biological data such as brain activity, hormone levels, or heart rate

physiological measures

Possibly due prior exposure to the test May not be the same across populations Vary across different types of tasks May be affected b regression toward the mean

practice effects

based on correlations of scores on one measure with those on a criterion measure taken at a later time.

predicitive validity

we tend to notice what is present and fail to consider the information of what is missing; failure to consider comparison groups.

present/past bias

eliminates confounds

random assignment

How strong is the association?? Is the relationship/association due to chance?

statistical validity of association claims

one variable must have temporal precedence (come first)

temporal precedence

simply involves measuring the same individuals twice and correlating their scores.

test-retest reliability

concurrent validity and predictive validity

types of criterion-related validity