AP Psych Unit 1 Part 2: Scientific Research Within Psychology

A key goal of experimental design is validity. Explain what this means.

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

What is the underlying logic when it relates to the possibility of obtaining results by chance?

When averages from two samples are each reliable measures of their respective populations, than their difference is probably reliable as well.

What is a histogram?

a bar graph depicting a frequency distribution.

operational definition

a carefully worded statement of the exact procedures (operations) used in a research study (examples: human intelligence = intelligence according to an intelligence test, sleep deprived = "x hours less" than a person's natural sleep)

standard deviation -

a computed measure of how much scores vary around the mean score

survey

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

What is a confounding variable?

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

What is sampling bias?

a flawed sampling process that produces an unrepresentative sample; usually involves generalizing from a few vivid unrepresentative cases.

What are scatter plots?

a graphed cluster of dots, each of which represents the values of two variables. The slope of said scatterplot suggests the direction of the relationship between the two variables. The less scattered the dots are, the higher indicated correlation.

What is correlation?

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

What is a skewed distribution?

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

What is an experiment?

a research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental processes (dependent variables). By random assignment of participants, the experimenter aims to control other relevant factors.

What is a random sample?

a sample that fairly represents a population because each member has an equal chance of participating or being included.

What is at the foundation of all science?

a scientific attitude that combines curiosity, skepticism, and humility.

What is a correlation coefficient?

a statistical index of the relationship between two things (from -1.00 to +1.00)

What is statistical significance?

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

What is a normal curve (normal distribution)?

a symmetrical bell-shaped curve that describes the distribution of many types of data; most scores fall within the mean and fewer and fewer near the extremes.

How do values affect psychological science?

affect our observations and interpretations, the way our labels describe and evaluate, and even popular applications. For example, what one person may see as faith, another may see as fanaticism or even in the case of art pieces where some may see a duck, another may see a rabbit, proving how subjective psychology may be.

When dealing with research, what is the population?

all those in the group being studied, from which samples may be drawn.It is the group you wish to study and describe.

What is a double-blind procedure? Why is it used?

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

What is the author's point to remember?

before any survey results are accepted, one must think critically and must consider the sample. The author notes that the best basis for generalization is via representative sample and that you cannot compensate for unrepresentative sample by adding more people.

What is random assignment? (don't confuse with random sample!)

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

What is the placebo effect?

describes experimental results caused by expectations alone.

What is meant by the amount of variation in the data?

describes how similar or diverse the scores are.

perceiving order in random events

describes our eagerness to make sense of our world; demonstrated by when we find patterns in random data (random sequences often don't look random) or are surprised by streaks of heads or tails

What is an illusory correlation?

describes perceiving a relationship where none exists or perceiving a stronger than-actual relationship.

overconfidence

describes the general idea that we think we know more than we actually do (ex: asked if boston is north or south of france etc.)

What is meant by regression toward the mean?

describes the tendency for extreme or unusual scores or events to fall back, or regress, towards the average.

hindsight bias

describes the tendency to believe, after learning an outcome, that one would have foreseen it all (aka the I-knew-it-all-along phenomenon)

What is meant by a "negative correlation"? Give an example.

describes when two sets of scores relate inversely, one going down as another goes up. An example of this would be the relation between people's height and the distance of their head to the ceiling.

What is meant by a "positive correlation"? Give an example.

describes when two sets of scores tend to rise or fall together. An example of this may be height and weight corresponding and rising or falling together (although this may not be always necessarily true) or test scores rising as the amount of sleep rises.

naturalistic observation

descriptive technique of observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation (examples: Twitter message moods by time and by day; Humans laughing 30 times more in social situations than in solitary situations; Happiest student participants avoided small talk and embraced meaningful conversations; Life is fastest paced in Japan and Western Europe and slower paced in economically less developed countries)

What is the point to remember?

doubt big, round, undocumented numbers, as they may often be guesses to emphasize or minimize a problem.

What is the point to remember when dealing with experiments?

experiments manipulate a variable to determine its effect, unlike correlational studies which naturally uncover occurring relationships.

theory

explains behaviors or events by offering ideas that organize observations; summarizes and simplifies

What are inferential statistics?

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

What are descriptive statistics?

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

How does the wording of questions influence responses on a survey?

people's interpretation of the question will change and influence their response. For example, people approve of "aid to the needy" more than when they hear "welfare".

Describing behavior is a first step toward

predicting it.

hypothesis

testable predictions; specify what results would support the theory and what results would disconfirm it

mean -

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores

Range -

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

What is an independent variable and give an example?

the factor in an experiment being manipulated and that's effect is being studied. An example of this could be a form of a study procedure being changed to determine which procedure is most effective.

What is a dependent variable and give an example?

the factor in an experiment that's outcome is being measured and that may change when the independent variable is manipulated. An example of this would be the final exam performance, in the case of the previously mentioned experiment.

define experimental group -

the group in an experiment exposed to the treatment (one form of the independent variable).

define control group -

the group in an experiment that is not exposed to the treatment that contrasts with the experimental group and serves as a comparison for evaluating the effect of the given treatment.

median -

the middle score in a distribution; half the scores are above it and half are below it

mode -

the most frequently occurring score(s) in a distribution

What is the main purpose of an experiment?

to test theoretical principles, rather than re-create exact behaviors of everyday life.

What are two reasons why psychologists study nonhuman animals?

to understand how different species learn, think, and behave as well as to better learn about people as we share a common biology.

What is key to approaching all of psychology?

understanding how research is done and how testable questions are developed and studied.

What are variables when discussing correlation?

variables can be anything that is feasible and ethical to measure.

What two issues emerge when debating if it is morally acceptable to use animals in research?

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?

For psychologists, statistics are the tools that allow them to:

Measure variables and then interpret results

What are the four main ethics codes when working with humans?

Obtain participants' informed consent to take part, Protect participants from greater than usual harm and discomfort, Keep information about individual participants confidential, Fully debrief participants

What three principles must be kept in mind when deciding when it is safe to generalize from a sample?

Representative samples are better than biased samples, Less-variable observations are more reliable than those that are more variable, More cases are better than fewer

What is the final point to remember for Unit 1?

Statistical significance indicates the likelihood that a result could have happened by chance, but does not say anything about the importance of the result.

three roadblocks to critical thinking

hindsight bias, overconfidence, percieving order in random events

case study

in-depth analysis of individuals or groups; examine one individual or group in depth in the hope of revealing things true to us all (examples: Brain damage- knowledge we have of the brain largely comes from case studies of individuals suffering from varied impairments after damage to a certain brain region; Children's minds- Jean Piaget's teachings about minds of children after observing and questioning a few children; Animal intelligence- studies of various animals to reveal capacity for understanding and language)

What does the experimenter intend in a laboratory environment?

intends the laboratory to be simplified reality that simulates and controls important features for everyday life.

Averages derived from scores with low variability are more

reliable than averages based on scores with high variability.

replication

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