Semester Final Review

hindsight bias

hindsight bias

the tendency to believe, after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all-along phenomenon.)

hypothesis

a testable prediction, often implied by a theory.

operational definition

a carefully worded statement of the exact procedures (operations) used in a research study. For example, human intelligence may be operationally defined as what an intelligence test measures.

replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances.

case study

a descriptive technique in which one individual or group is studied in depth in 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

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

sampling bias

a flawed sampling process that produces an unrepresentative sample.

population

all those in a group being studied, from which samples may be drawn.

random sample

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

correlation

a measure of the extent to which two variables change together, and thus of how well either variable predicts the other.

correlation coefficient

a statistical index of the strength of a relationship between two variables (from -1 to +1).

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. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation).

illusory correlation

the perception of a relationship where none exists.

experiment

a 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). By random assignment of participants, the experimenter aims to control other relevant variables.

experimental group

in an experiment, the group exposed to the treatment, that is, to one version of the independent variable.

control group

in an experiment, 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.

double-blind procedure

an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.

independent variable

the experimental factor that is manipulated; the variable whose effect is being studied.

confounding variable

a factor other than the independent variable that might produce an effect in an experiment.

dependent variable

the outcome factor; the variable that may change in response to manipulations of the independent variable.

validity

the extent to which a test measures or predicts what it is supposed to.

descriptive statistics

numerical data used to measure and describe characteristics of groups. Includes measures of central tendency and measures of variation.

histogram

a bar graph depicting a frequency distribution.

mode

the 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. Most affected by outliers.

median

the middle score in a distribution; half the scores are above it and half are below it. Best measure when there are outliers.

skewed distribution

a representation of scores that lack symmetry around their average value - outliers.

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 (normal distribution)

a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean (about 68 percent fall within one standard deviation of it) and fewer and fewer near the extremes.

inferential statistics

numerical data that allow one to generalize—to infer from sample data the probability of something being true of a population.

statistical significance

a statistical statement of how likely it is that an obtained result occurred by chance.

informed consent

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate.

debriefing

the postexperimental explanation of a study, including its purpose and any deceptions, to its participants.

placebo effect

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.

false consensus effect

the tendency to overestimate the extent to which others share our beliefs and behaviors

confirmation bias

a tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence

belief perseverance

clinging to one's initial conceptions after the basis on which they were formed has been discredited

encoding

the processing of information into the memory system—for example, by extracting meaning.

storage

the process of retaining encoded information over time.

retrieval

the process of getting information out of memory storage.

sensory memory

the immediate, very brief recording of sensory information in the memory system.

short-term/working memory

activated memory that holds a few items briefly, such as the seven digits of a phone number while dialing, before the information is stored or forgotten - conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long-term memory.

long-term memory

the relatively permanent and limitless storehouse of the memory system. Includes knowledge, skills, and experiences.

explicit memory

memory of facts and experiences that one can consciously know and "declare." (Also called declarative memory.)

effortful processing

encoding that requires attention and conscious effort.

automatic processing

unconscious encoding of incidental information, such as space, time, and frequency, and of well-learned information, such as word meanings.

implicit memory

retention independent of conscious recollection. (Also called non-declarative memory or procedural.)

iconic memory

a momentary sensory memory of visual stimuli; a photographic or picture-image memory lasting no more than a few tenths of a second.

echoic memory

a momentary sensory memory of auditory stimuli; if attention is elsewhere, sounds and words can still be recalled within 3 or 4 seconds.

chunking

organizing items into familiar, manageable units; often occurs automatically.

mnemonics

memory aids, especially those techniques that use vivid imagery and organizational devices.

spacing effect/distributed practice

the tendency for distributed study or practice to yield better long-term retention than is achieved through massed study or practice.

shallow processing

encoding on a basic level based on the structure or appearance of words.

deep processing

encoding semantically, based on the meaning of the words; tends to yield the best retention.

hippocampus

a neural center located in the limbic system; helps process explicit memories for storage.

flashbulb memory

a clear memory of an emotionally significant moment or event.

long-term potentiation (LTP)

an increase in a cell's firing potential after brief, rapid stimulation. Believed to be a neural basis for learning and memory.

recall

a measure of memory in which the person must retrieve information learned earlier, as on a fill-in-the-blank test.

recognition

a measure of memory in which the person need only identify items previously learned, as on a multiple-choice test.

relearning

a measure of memory that assesses the amount of time saved when learning material again.

priming

the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response.

mood-congruent memory

the tendency to recall experiences that are consistent with one's current good or bad mood.

anterograde amnesia

an inability to form new memories.

retrograde amnesia

an inability to retrieve information from one's past.

proactive interference

the disruptive effect of prior learning on the recall of new information.

retroactive interference

the disruptive effect of new learning on the recall of old information.

repression

in psychoanalytic theory, the basic defense mechanism that banishes from consciousness anxiety-arousing thoughts, feelings, and memories.

misinformation effect

incorporating misleading information into one's memory of an event.

source amnesia

attributing to the wrong source an event we have experienced, heard about, read about, or imagined. (Also called source misattribution.) Source amnesia, along with the misinformation effect, is at the heart of many false memories.

cognition

all the mental activities associated with thinking, knowing, remembering, and communicating.

concept

a mental grouping of similar objects, events, ideas, or people.

prototype

a mental image or best example of a category. Matching new items to a prototype provides a quick and easy method for sorting items into categories (as when comparing feathered creatures to a prototypical bird, such as a robin).

creativity

the ability to produce novel and valuable ideas - rigid mental sets can inhibit

convergent thinking

narrows the available problem solutions to determine the single best solution.

divergent thinking

expands the number of possible problem solutions (creative thinking that diverges in different directions).

algorithm

a methodical, logical rule or procedure that guarantees solving a particular problem. Contrasts with the usually speedier—but also more error-prone—use of heuristics.

heuristic

a simple thinking strategy that often allows us to make judgments and solve problems efficiently; usually speedier but also more error-prone than algorithms.

insight

a sudden realization of a problem's solution; contrasts with strategy-based solutions.

confirmation bias

a tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence.

mental set or schema

a tendency to approach a problem in one particular way, often a way that has been successful in the past.

intuition

an effortless, immediate, automatic feeling or thought, as contrasted with explicit, conscious reasoning - faulty, has limits

representativeness heuristic

judging the likelihood of things in terms of how well they seem to represent, or match, particular prototypes; may lead us to ignore other relevant information.

availability heuristic

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.

overconfidence

the tendency to be more confident than correct—to overestimate the accuracy of our beliefs and judgments.

belief perseverance

clinging to one's initial conceptions after the basis on which they were formed has been discredited.

framing

the way an issue is posed; how an issue is framed can significantly affect decisions and judgments.

language

our spoken, written, or signed words and the ways we combine them to communicate meaning.

phoneme

in a language, the smallest distinctive sound unit.

morpheme

in a language, the smallest unit that carries meaning; may be a word or a part of a word (such as a prefix).

grammar

in a language, a system of rules that enables us to communicate with and understand others. In a given language, semantics is the set of rules for deriving meaning from sounds, and syntax is the set of rules for combining words into grammatically sensible sentences.

babbling stage

beginning at about 4 months, the stage of speech development in which the infant spontaneously utters various sounds at first unrelated to the household language.

telegraphic speech

early speech stage in which a child speaks like a telegram—"go car"—using mostly nouns and verbs.

Broca's area

controls language expression—an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.

Wernicke's area

controls language reception—a brain area involved in language comprehension and expression; usually in the left temporal lobe.

linguistic determinism

Whorf's hypothesis that language determines the way we think.

context effects

memory is aided by being in the physical location where encoding took place

semantic encoding

the process of relating new information in a meaningful way to knowledge that is already stored in memory