Unit 0

Psychology

Psychology's findings are a result of a scientific approach, based on careful observation and testing.

Scientific Attitude

Scientific attitude equips us to be curious, skeptical and humble in scrutinizing competing ideas or our own observations.

Critical Thinking

Critical thinking puts ideas to the test by examining assumptions, appraising the source, discerning hidden biases, evaluating evidence, and assessing conclusions.

Common Sense Issues

A. Our countless casual observations are wrong. B. Repetition of statements, true or false, make them easier to process and remember.

Hindsight Bias

Tendency to believe, after learning the outcome, that one would have foreseen it....Know-it-all-phenomenon.

Overconfidence

We tend to think that we know more than we do.

Perceiving Order in Random Events

We tend to find patterns when none really exist.

Scientific Method

A self-correcting process for evaluating ideas with observation and analysis.

Peer Reviewers

Scientific experts who evaluate a research article's theory, originality, and accuracy.

Theory

An explanation using an integrated set of principles that organizes observations and predicts behaviors or events.

Hypothesis

A testable prediction, often implied by a theory.

Falsifiable

The possibility that an idea, hypothesis, or theory can be disproven by observation or experiment.

Operational Definition

A carefully worded statement of the exact procedures (operations) used in a research study.

Replication

Repeating the essence of a research study, usually with different participants and different situations, to see whether the basic finding can be reproduced.

Case Study

One individual or group is studied in depth with the hope of revealing universal principles.

Naturalistic Observation

Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation.

Survey

Technique for obtaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group.

Experimental Methods

Manipulate variables to see their effects.

Social Desirability Bias

Bias from people's responding in ways they presume a researcher expects or wishes.

Self-Report Bias

Bias when people report their behavior inaccurately.

Sampling Bias

Flawed sampling process that produces an unrepresentative sampling.

Random Sample

Sample that fairly represents a population because each member has an equal chance of inclusion.

Population

All those in a group being studied, from which random samples may be drawn

Correlational research

Describes the relationship between two or more variables

Experimental methods

Attempt to establish a cause and effect relationship

Correlation

Measure of the extent to which two factors vary together, and thus how well either factor predicts the other

Correlation Coefficient

Statistical index of the relationship between two variables (between -1.00 and +1.00)

Variable

Anything that can vary and is feasible and ethical to measure

Scatterplot

A graphed cluster of dots, each of which represents the values of two variables

Positive Correlation

Two sets of scores tend to rise or fall together

Negative Correlation

Two sets of scores relate inversely, as one rises the other falls

Illusory Correlation

Perceiving a relationship where none exists, or perceiving a stronger-than-actual relationship

Regression Toward the Mean

Tendency for extreme or unusual scores or events to fall back (regress) toward the average

Experiment

Research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable)

Experimental Group

The group exposed to the treatment, that is, to one version of the independent variable

Control Group

The group not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment

Random Assignment

Assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups

Single-Blind Procedure

Experimental procedure in which the research participants are ignorant (blind) about whether they have received the treatment or a placebo

Double-Blind Procedure

Experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether they have received the treatment or a placebo

Placebo Effect

Experimental results caused by expectations alone

Independent Variable

The factor that is being manipulated; the variable whose effect is being studied

Confounding Variable

A factor other than the factor being studied that might influence a study's results

Experimenter Bias

Bias caused when researchers may unintentionally influence results to confirm their own beliefs

Dependent Variable

Outcome that is measured; the variable that may change when the independent variable is manipulated

Validity

The extent to which a test or experiment measures or predicts what it is supposed to

Quantitative Research

Research method that relies on quantifiable, numerical data

Qualitative Research

Research method that relies on in-depth narrative data that are not translated into numbers

Purpose of an experiment

For the lab environment to be a simplified reality; one that simulates and controls important features of everyday life

Animal Experimentation Issues

Is it right to place the well-being of humans above that of other animals? What safeguards should protect the well-being of animals in research?

APA Guidelines for Animal Experimentation

Researchers must provide 'humane care and healthful conditions' and that testing should 'minimize discomfort.'

APA Testing Code of Ethics for Human Research

1. Obtain potential participants' informed consent. 2. Protect participants from greater-than-usual harm and discomfort. 3. Keep information about participants confidential. 4. Debrief participants (explain the research afterward, including any temporary deception).

What can get a scientist banned from their profession?

Fraud.

Psychologists' Values

Psychologists' Values affect what we study, how we study, and how we interpret results.

Descriptive Statistics

Numerical data used to measure and describe characteristics of groups; includes measures of central tendency and measures of variation.

Histogram

Bar graph depicting a frequency distribution.

Central Tendency

A single score that represents a whole set of scores.

Mode

Most frequently occurring score(s) in a distribution.

Mean

The arithmetic average of a distribution; obtained by adding the scores and then dividing by the number of scores.

Median

The middle score in a distribution, half the scores are above it and half are below it.

Percentile Rank

The percentage of scores that are lower than a given score.

Skewed Distribution

A representation of scores that lack symmetry around their average value.

Range

The difference between the highest and lowest scores in a distribution.

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.

With a normal curve, what percentage of the scores will be within 1 standard deviation on either side of the mean?

68%

With a normal curve, what percentage of the scores will be within 2 standard deviations of the mean?

95%

Inferential Statistics

Numerical data that allows one to generalize-to infer from sample data the probability of something being true of a population.

Meta-Analysis

Statistical procedure for analyzing the results of multiple studies to reach an overall conclusion.

Principles for Inferring Population Difference

1. Representative samples are better than biased (unrepresentative) samples. 2. Bigger samples are better than smaller samples. 3. More estimates are better than fewer estimates.

Null Hypothesis

Assumption that no difference exists between groups.

Statistical Significance

Statistical statement of how likely it is that a result (such as a difference between samples) occurred by chance, assuming there is no difference between the populations being studied.

P-Value

Indicates the probability of a result, given the null hypothesis; Strong evidence that we can reject the null hypothesis (no-difference) occurs when the probability (p-value) is less than 5% (.05).

Effect Size

Strength of relationship between two values; The larger the effect size, the more one variable can be explained by the other.

Confidence Interval

Range of values that likely include the population's true mean value.