AP Psych Unit 0

Modern Definition of Psychology

the scientific study of behavior and mental processes

Definition of Scientific method

A self correcting process for evaluating ideas w/ observation and analysis

Three elements that make a theory useful

1. Organizes observations

2.Implies predictions that anyone can use to check the theory

3. Stimulates further research that leads to a revised theory that better organizes products

Operational Definition*

statement of the exact procedures (operations) used in a research study

Case study*

a non experimental technique in which an individual is studied in depth in the hope of revealing universal principles

Naturalistic observation*

a non experimental technique of observing and recording behavior in a naturally occurring situation without trying to manipulate the situation

Bias*

In psychological research, bias refers to errors in research that lead to distorted results or wrong conclusions.

Phases of research that bias can occur*

Bias can occur during data collection, data analysis, interpretation, or publication.

Self report bias*

Bias when people report their behavior inaccurately

Social desirability bias*

When people give answers that make them look good

Sampling bias*

the people surveyed don't accuratley represent the population the researchers are interested in

How can researchers avoid sampling bias?*

Obtain a representative sample, a common way to do this is by using random sampling

Population*

All people who can potentially participate in the study

Psychologists want to ___________ what they learned from a study to all people in a population

generalize

Why is a representative sample important?*

Allows scientists to generalize w/ the larger population

Correlational research*

Non-experimental research method which describes the relationship between two or more variables

Correlation*

A statistical measure of the extent to which two variables are related, and thus of how well either variable predicts the other

Positive correlation*

Two variables move in the same direction (both go up or down)

Negative correlation*

Two variables move in the opposite direction (one goes up, other goes down)

Scatterplot*

a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. Direction can be positive or negative.

What does the amount of scatter suggest?*

the strength of the correlation (little scatter indicates high correlation)

What is the correlation coefficient?*

The statistic used to describe the strength and direction of the relationship between two variables. It ranges between -1.0 and +1.0.

How is the correlation coefficient interpreted?*

A positive correlation coefficient indicates a positive relationship between variables, while a negative correlation coefficient indicates a negative relationship.

How does the number value of a coefficient reflect the strengths of the correlation?*

the closer the value is to -1 or +1, the stronger the relationship between two values.

Does correlation prove causation?*

Correlations help us predict. However, knowing two variables are correlated does not explain how or why they are related.

Directionality problem*

a problem encountered in correlational studies; you cannot determine which variable may have caused changes in the other variable

The third variable problem*

illustrates why correlation does not prove causation. A 3rd variable such as distressing events, or biological predisposition, may lead to both low self esteem and depression

Reliability*

The degree to which results are stable and consistent. One way to evaluate reliability is to replicate the research under the same conditions, if the results can be achieved again, then the study is reliable.

Validity*

The ability of a test to measure what it is intended to measure. The likelihood that the dependent variable is actually caused by the independent variable.

Quantitative data

Numbers, objective and measurable

Qualitative

Subjective and structured, words.

Independent variable*

variable that is manipulated

Dependent variable*

variable that is measured

Operational definitions

a statement of the procedures used to define research variables

Random selection*

everyone in the population has an equal chance of being chosen for the experiment

Experimental group*

Independent variable is manipulated

Control group*

Comparison groups that do not receive the special treatment

Placebo effect*

Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recepient assumes is an active agent. Solution to this is a placebo group

Random assignment*

All members have an equal chance of being placed in any type of group

Why do we randomly assign?*

Randomly assigning participants to experimental and control conditions minimizes pre-existing differences between groups.

Institute experimental controls*

In order to isolate the impact of the independent variable on the dependent variable, researchers attempt to control as many other factors as possible between the groups.

Single blind procedure*

research design in which participants don't know whether they are in the experimental or placebo

Double blind procedure*

An experimental procedure in which both the research participants and the researcher staff are ignorant about weather research participants have received the treatment or a placebo.

Confounding variable*

a factor other than the independent variable that might influence a study's results

Examples of confounding variables*

-Sampling bias

-Pre-existing differences between subjects

-Varied conditions between the experimental and control group

-Participant bias

-self report, social desirability bias

-experimenter bias

How to prevent sampling Bias?*

Can be adressed by random sampling

how to prevent pre-existing differences?*

random assignment

how to prevent participant bias?*

placebo group, single blind group

how to prevent experimenter bias?*

double-blind procedure

Strengths of experimental research

conclusions about cause and effect can be drawn

weakness of experimental research

vulnerable to error. Flaws in research design or experimental procedures can lead to misleading results or mistaken conclusions.

No coercion*

Each participant has the right to confirm or deny participation in a study without being forced or threatened.

Informed consent

Participant must give signed consent. For participants under 18 a parent must sign for them, and the child must comply

Protection from harm/discomfort*

The APA requires that researchers protect participants from greater than usual harm and dicomfort. No long term consequences.

Limited deception*

Misleading participants about the nature of an experiment

Confederate

person who pretends to be a participant but is actually part of the research team

When is deception acceptable?

when researcher believes it's necessary for the study, and the IRB agrees.

Debriefing*

The explanation of a study after it's over. Must explain purpose and deceptions

Confidentiality*

protects the private info of research participants. Information from the study cannot be shared with anyone outside the research team without consent from the participants.

Ethics Checklist*

coercion

informed consent

protection from harm/discomfort

anonymity

confidentiality

deception

debriefing

Mode*

most frequently occurring scores

Mean*

average

Median*

Midpoint of all data, same amount of #s on top and bottom.

Extreme scores (outliers)*

Distortion of data by either a super high/low data point

normal distribution (aka bell curve)*

a symmetrical distribution with values clustered around a central, mean median and mode value

Positively skewed distribution*

many low scores and few high scores, mean is pulled toward high scores

Negatively-skewed distribution

many high scores and few low scores, mean is pulled toward low scores

Measures of variation*

measures of central tendency provide basic information about data set but do not reveal the amount of variation in the data, meaning how widely spread the scores are from eachother. (highest score-lowest score)

Standard deviation*

a measure of variability that describes an average distance of every score from the mean

Normal distribution rule*

34%, 13.5%, 2%

Inferential statistics*

A branch of statistics that make use of various analytical tools to draw inferences about the population from sample data

When is an observed difference reliable?*

1. Representative samples are better than biased samples

2. Less-variable observations are more reliable than those that are more variable

3. More cases are better than fewer

when is an observed difference significant?*

-researchers use inferential statistics to estimate the probability of a result occuring by chance

-researchers begin with the assumption that no difference exists between the groups

-researchers refer to this default assumption as the "null hypothesis"

-next they conduct a test of statistical difference

How do we test for statistical significance?*

-a probability value, or P value, gives the probability that the null hypothesis is true and the difference between groups iin due to chance

- the level of statistical significance in often expressed as a P value between 0-1

-the smaller the P value the more significant the results are

- a P value of 0.5 is the cutoff for statistical significance

What factors influence statistical significance?*

sample size: larger sample size makes a lower P value

-effect size: effect size refers to the magnitude of the difference between the group means. Larger effect size can contribute to lower p value.

-variability: a lower SD can contribute to a lower P value