PSY 230 Quiz 2

Non-directional

Different Short term mating orientation will differ between men and women (Doesn't say WHAT the difference is)

directional

Larger/smaller, higher/lower, positive/negative association (Adding a specific direction) Men will have higher STMO score compared to women

Content validity

- Do the items measure all aspects of what we want to measure? • Example: depression - affect, behavior, physical • When you want to know whether a sample of items truly reflects an entire universe of items on a certain topic • How to Establish . . . - Content expert - Do items represent all possible items? - Course or Class: How well does the number of items reflect what was taught?

Criterion validity

- Does the measure correlate (or not correlate) with theoretically relevant items? • Concurrent criterion validity: • Predictive criterion validity: extent to which a measure is related to an outcome -• When you want to know if test scores are systematically related to other criteria • Concurrent criterion validity: How well a test outcome is consistent with a criterion that exists in the present - Personality measures with theoretically-related measures • Predictive criterion validity: How consistent a test outcome is with a criterion that occurs in the future - A measure of CVD risk with hard measures of CVD outcomes

degree of deviation

- Make scores interpretable (where are you relative to the mean?) • Z-scores measure the _______________ from the mean in units of standard deviation (+/-) • Usually ranges from -3 to +3 - Mean = 0 - SD = 1

reliability coefficients

- The reliability coefficients to be positive and not to be negative - Reliability coefficients that are as large as possible (between 0.00 and +1.00) • ~.75

sources of error

- testing situations or conditions that impact the obtained score rather than the qualities of the trait being measured. - Example: Whether the temperature of the room impacts the test score

normal distribution

- unimodal, - bell-shaped - symmetric around the mean

z score

1. transform raw scores into scores that have more information (exact location of the X value in the distribution) 2. standardize distributions (allows comparison to other distributions that have also been transformed into z-scores)

sign and number

2 components of z score

null/research

2 major types of hypothesis

z-scores 0 to +1

34.13% of scores

z-scores 0 to +2

47.72% of scores

z-scores -1 to +1

68.3% of scores

z-scores -3 to +3

99.7% of scores

directional research hypothesis

A _______ is a hypothesis that reflects the difference between groups and also specifies the direction of the difference.

testable

A hypothesis is a ________ Statement: o Translates the problem or research question into a form that can be tested Ex of research statement: how does experiencing weight stigma affect eating?

z-score

A standard score that is the result of dividing: A. the amount that a raw score differs from the mean of the distribution by B. the standard deviation

unsystematic

Stuff you can't really control for (Noise) - Randomize, Counterbalance

z score

The _______ is the most commonly used standard score.

true score

The actual or measured score is called the _______.

test-retest reliability

The correlation between scores from Time 1 and Time 2 is called _______.

asymptotic

The fact that the tails of a normal distribution never touch the horizontal axis relates to the following property: ______.

sample

The group you actually collect data from for your study is known as the _______.

independent variable

The more violent television programs an individual watches, the more likely the individual develops aggressive behavior. Watching violent television is ______.

mean and standard deviation

The normal curve is... - defined by 2 PARAMETERS:

dependent variable

The outcome variable in an analysis is also called the _______.

True score

The true, 100%-accurate reflection of what you really know - Rarely are the observed and true scores the same.

14%

Under the normal curve, approximately what percentage of scores falls between -1 and -2 standard deviations below the mean?

z score

What type of standard score has M = 0 and SD = 1?

observed score

What you actually get on a test (e.g., 89 or 65)

Parallel-forms reliability

When you want to know if several different forms of a test are reliable or equivalent - Example: Split items up that purport to measure the same thing and correlate

Internal-consistency reliability

When you want to know if the items on a test assess one—and only one—dimension - Example: do all these items go together?

Test-retest reliability

When you want to know whether a test is reliable over time - Example: A personality test taken and then taken again a month later

Interrater reliability

When you want to know whether there is consistency in the rating of some outcome - Do these raters agree

There is a positive relationship between a high-fat diet and weight gain.

Which of the following is an example of a directional hypothesis?

they are negative

Which of the following is true of z scores that fall below the mean?

predictive validity

Which of the following validities is concerned with monitoring estimates of future performance?

Construct validity

_______ is based on the judgment of how well a test reflects an underlying idea.

content validity

_______ is established by consultation with an expert on the topic focused upon by your instrument.

Research hypotheses

can be directional and nondirectional

Platykurtic

flat distribution

Kurtosis

how peaked and pointy the distribution is

independent variable

is the treatment.

reliability

means that the measure is consistent in measuring what it was designed to measure. It is whether a test—or whatever you use as a measurement tool—measures something consistently

Validity

means that the test, scale, or instrument measures what it is supposed to.

null

nothing, no difference, no inequalities between groups

true

null hypothesis is accepted as ___ without knowing more information

z score

number of standard deviations that a raw score is above/below the distribution mean

raw score

original, unchanged score that is direct result of measurement (X) without context, raw score doesn't tell you much e.g score of X = 76

Null hypothesis

refer to populations and are written in Greek Symbols

Research hypothesis

refer to samples and are written in Roman symbols

standard deviation

the amount one would intuitively expect that a random observation would differ from the mean

Construct validity

the degree to which it measures - Do all these items go together? • How well a test reflects an underlying idea or construct - intelligence or aggression • Most interesting . . . most difficult source of validity to establish • Want your construct to correlate with related behaviors and not to correlate with behaviors that are not related

Population

the large group to which you would like to generalize your findings

sampling error

the measure of how well a sample represents the population o Deviation away from the population parameters o Example: interested in pregnant latino mothers; you would not take a sample of males

sample

the smaller, representative group of the population that is used to do the research

Leptokurtic

very peaked

dependent variable

what the researcher looks at to see whether any change has occurred as a function of the treatment.

valid

• A ______ test is one that measures what it is supposed to measure.

distribution

• A ______________ is the summary of how likely (probable) a value or range of values may be. The area under the curve indicates this likelihood.

reliable

• A test can be _______ but not valid.

valid

• A test cannot be ______ unless it is reliable because if a test does what it is supposed to, then it has to do it consistently to work.

Hypothesis

• An educated guess - informed by past research or theory

significance

• How unlikely an event (or association) might be - P < .05 - z-score of +1.96 (P-values Smaller is better!!) - When your probability falls below 5%, we assume that the event may have some reason for occurring (not by chance)

Establishing reality

• Increase the number of items. • Delete unclear items. • Make the test neither too easy nor too hard. • Reduce the effects of external distractions.

normal curve

• Provides a visual representation of a distribution of scores • Mean, median, and mode are equal to one another • Tails are asymptotic (get closer to horizontal axis but never touch it)

Directional Research Hypothesis:

• Reflect a difference, and the direction is specified • Use a ONE tailed test

non-directional research hypothesis

• Reflect a difference, but the difference is not specified • Use a TWO-tailed test (Use this because the direction is not specified) • H1 : X1 ≠ X2 • States that they are not equal to each other

research hypothesis

• Statement that there is a relationship between two variables • Statements of inequality • There are two types of research hypothesis

Null hypothesis

• Statements that contain two or more things that are equal (unrelated) to each other

Probability

• The areas of the curve that are covered by different z-scores also represent the __________ of a certain score occurring.

z score

• They tell you where your score was relative to scores drawn from a normal distribution.

Probability

• To determine the likelihood that an effect/difference was generated by random chance (the Null Hypothesis).

reject

• We cannot prove the research hypothesis BUT we can _____ the null

Probability

• We reject the Null Hypothesis based on _______ - This effect was likely not caused by chance - We can infer that the effect (relationship) exists but we cannot prove it • Normal Distribution

nature

• What makes the normal distribution special is that many processes in _____, when randomly sampled, produce observations that are normally distributed.

hypothesis and Z scores

• When we put together_____________ you will be able to estimate how likely certain outcomes (specified in the research hypothesis) are.

likelihood

• With the mean and standard deviation, you can predict the ______ of ANY real number drawn from this distribution.

good hypothesis

• be stated in declarative form • posit a relationship between variables • reflect a theory or a body of literature on which they are based • be brief and to the point, and • be testable.

systematic

Deliberate like a manipulation (Signal)

observed - true

Error =

Skewness

How lopsided or not symmetrical the distribution is

mean and standard deviation

If you want to calculate a z score for a test where your raw score was 24, what other information must you know?

construct validity

If you want to know that a test measures some underlying psychological construct, what type of validity evidence would you want to collect?

test-retest reliability

If you want to know whether a test is reliable over time, what type of reliability do you use?

dependent variable

If you wanted to examine the impact of fast-food consumption on weight gain, your measurement of weight gain would be the _______.

observed score

In terms of the reliability of test scores, there are multiple elements to each person's score. The score that is actually recorded is the _______.

normal distribution

Large samples approximate a

Variability

Spread across numbers