psyc 60 steiner quiz #1

Procedures for describing data

Mean, median, and mode

Procedures for drawing conclusions about data

Correlation, regression, t-tests, f tests

The complete set of events in which you are interested.

All Pysch 60 students at UCSD.

Numerical values summarizing population data.

The average final grade of all PSYCH 60 students at UCSD.

A set of actual observations: subset of a population

A section of PSYCH 60 students at UCSD.

Numerical values summarizing sample data

The average final grade of this section of PSYCH 60 students at UCSD

A sample in which each member of the population has an equal chance of inclusion.

It increases the chance that the sample will be representative of the population.

Random number generator Table of random numbers Records, locations, processes, etc. that provide representative samples.

Measurement(quantitative) data and Categorical(frequency or count data)

Data obtained by measuring objects or events.

Numbers that represent aggression, height, working memory capacity, etc.

Data representing counts or numbers of observations in each category.

"23 instructors were in favor of the new curriculum and 27 were not"

Numbers used only to distinguish objects

An athlete's # or label Gender, male, female, nonbinary. (1 = male)(2 = female)(3 = nonbinary)

Numbers used only to place objects in order.

"Rank: 1st, 2nd, 3rd" More than labels, specific ranking Dawn, day, dusk, night. (sequence)

A scale on which equal intervals between objects represent equal differences - differences are meaningful

Temperature: 0 degrees does not mean there's no temperature.

A scale where true zero point-ratios are meaningful

Length, weight, volume, speed, hormones, etc. All measured on ratio scales. A zero means no quantity A swimmer's lap/speed

Properties of objects or events that can take on different values.

Anything that can be measured is a variable Height, speed, gender, etc.

Variables that can take on a small set of possible values. Gender, marital status, number of TV's in your house.

Variables that can take on any value Height, speed, cortisol, working memory capacity

Those variables controlled by the experimenter.

The variables being measured: the data or score. IV is manipulated, DV is measured

The allocation of participants to groups by a random process.

A distribution in which the values of the dependent variable are tabled or plotted against their frequency of occurrence.

A graph in which a rectangle is used to represent frequencies of observations within each interval.

The vertical axis

The horizontal axis

A graphical display presenting original data arranged into a histogram.

The leftmost digits in a number The 1 in 15

The digits to the right of the leading digits. The 5 in 15

Vertical axis of display containing the lead digits

Horizontal axis of display containing the trailing digits.

A graph in which the y values corresponding to different values of x are connected by a line.

A graph in which the frequency of occurrence of different values of x is represented by the height of a bar.

Having the same shape on both sides of the center.

Ex. IQ scores distribution

A distribution of having one distinct peak

Ex. IQ scores distribution

A distribution having two distinct peaks

Ex. Scores on an exam where there are a lot of Cs and As, but barely any Fs, Ds, and Bs.

The term is used to refer to the number of major peaks in a distribution.

Or mode. In distribution, it's represented in peaks.

The degree to which a distribution is asymmetrical. No skew is perfectly symmetrical.

A distribution that rails off to the left.

Ex. A distribution of exam scores when the exam is easy. Data is trailing off of the left

A distribution that trails off to the right.

Ex. Lots of scores on the left end and trails off to the right Low to High scores

A measure of the center of a distribution. Often mean, median, or mode.

The most commonly occurring score.

The score corresponding to the point having 50% of the observations below it when the observations are arranged in numerical order.

The location of the median in an ordered series: (N + 1) / 2 It's the middle number in an odd set of ordered numbers

The sum of scores divided by the number of scores The mean is the average.

The degree to which individual data points are distributed around the mean.

Refers to how much scores vary or differ from the mean

The distance from the lowest to highest score.

Ex. highest is 5, lowest is 1 = 5 - 1 = 4

An extreme point that stands out from the rest of the distribution.

The range of the middle 50% of the observations.

two inner 25% are the inner half = 50%

The Sum

The number of observations in a population

The number of observations in a sample

Population mean

Sample Mean

Sample variance - The sum of the squared deviations from the mean, divided by N - 1

Sample Standard Deviation - The square root of the sample variance. Rough idea (The average deviation from the mean)

Population variance

Population standard deviation

The number of independent pieces of information remaining after estimating one or more parameters.

A graphical representation of the dispersion of a sample.

A specific distribution having a characteristic bell-shaped form. Ex. IQ scores are normally distributed, they fall on a normal distribution.

A normal distribution with a mean equal to 0 and variance equal to 1. Uses z scores!

The number of standard deviations above or below the mean. z scores range from -4 to +4 if its a perfectly normal distribution.

The point below which a specified percentage of the observations fall.