Problem Set #1 Terms Flashcards
What is APA Style?
Writing style that has become the standard for professional writing in psychology.
What is the average deviation?
A measure of variation. or spread, that indicates the average difference between the scores and the mean in a distribution.
What is a bar graph?
A graph where the vertical bars represent means of the dependent variable and are centered above each category of the independent variable along the x-axis.
Separated from each other by a space indicating that the levels of the independent variable represent distinct, non-continuous categories.
What is a bar histogram?
A graph of frequency distribution in which the vertical bars represent the frequency of each score or group of scores in the distribution.
What is a bell curve?
A term used in the popular culture to describe the shape of the Gaussian curve or standard normal frequency distribution.
Who created the bell curve?
Carl Fredrick Gauss
What is a box plot?
A graph that depicts the overall distribution of a data set.
- See notes/Wikistat if you need visual
Who created the box plot?
John Tukey
Originally called “box and whisker plot”
What is the central limit theorem?
?
What is a central trend?
A descriptive statistic that represents the center of a data set
The value that all the data seems to gather around
What are the commonly used measures of central trend?
The mean, median, and mode`
What is chart junk?
Unnecessary information or features in a graph
What is confidence interval (descriptive)?
This gives us a point and interval estimate for the mental processes and behaviors we are studying (samples of people).
What is the point estimate in the confidence interval (descriptive)?
The Mean; this is our “best point estimate” for the population mean
What is the interval estimate in the confidence interval (descriptive)?
Confidence interval; range within which the true population mean is likely to lie.
What is a convenience sample?
A sample of readily available people, not a random sample from the entire population of interest
What is a continuous variable?
A variable that falls along continuum and often has fractional amounts (decimated numbers)
What is a dependent variable?
It is the variable we measure and what we hypothesize depends on or is related to, or caused by, changes in the independent variable
This is our data, what the data we are putting into the computer to measure
What is descriptive statistics?
Describes a distribution by providing information about its central trend, its width, and its shape.
Common ones are: mean, median, mode, the range and standard deviation, and the skew – plus a variety of graphs
What is discrete variable?
variable that is usually measured in whole numbers and each number is distinct from the other numbers.
Usually has limited number of values.
Common ones are: gender, number of speeding tickets, scores on personality tests.
What is a dot plot/dot and whisker?
Graph which a dot is used to represent the mean of a set of scores and a whisker to represent one standard deviation about and below the mean
What is an error bar graph?
Graph of cell means that is often used when there are 3 or more groups in our analysis.
What does the dot in the middle of the error bar graph mean?
It’s the mean
What do the lines above and below the dot in the error bar graph mean?
Represents the 95% confidence interval for that mean.
What does EDA stand for?
Exploratory Data Analysis
What is EDA?
Effort to summarize our data, often with visual displays.
What is extraneous variable?
Randomly distributed influence the detracts from our efforts to measure what we intend to measure.
What is a figure?
In APA writing a figure is any visual presentation of data, like a photograph, drawing, or graph.
What is first quartile?
The 25th percentile of a data set.
Usually displayed in a box plot as the bottom of the box
What is a frequency polygon
A smoothed line graph of the frequencies of each score.
What is the most common frequency polygon?
Standard normal frequency polygon, popularly known as the bell curve**
What is generalizability?
Our ability to apply findings from a study of one sample or in one context to other samples or contexts
What isa pictorial display of quantitative information?
a graph
What is heterogenous?
Consisting of dissimilar elements
What is homogenous?
Uniform or similar in kind
What is the independent variable?
The variable in the study that we manipulate or select for.
This variable usually identifies each group in the study and appears on the horizontal axis of a graph of the group means. — What’s the variable name?
Independent variable
What is interval scale?
A scale of measurement in which the units are all equal in size, but the zero point is arbitrary
What is the measure of central trend?
A number that describes a set of scores by indicating its center or middle
What are the common measures of the central trend?
Mean, Median, and Mode
Define median
A measure of central trend
The middle score in a set of scores after the scores have been arranged lowest to highest.
I.E. — 2 4 5 6 7 8 9 –> 6 is the median
Define mode?
A measure of central trend
The score in a distribution tat is the most frequent
What is a negative skew?
A distribution in which the peak is to the right of the center point, so the scores are piling up at the top of the distribution
- See picture in notes
Define nominal scale
Scale in which objects or individuals are divided into categories and numerals are assigned to the categories just to name them.
Examples: Gender, personality type (introvert/extrovert)
Define normal distribution.
A theoretical frequency distribution with special characteristics
** See pictures in notes
Define operational.
Defining a variable in terms of the operations (activities) we use to measure or manipulate it.
What is ordinal scale?
A scale on which individuals or attributes are categorized along a continuum of ranks.
What is a common ranking system we use?
Ordinal Scale**
Likert Scale
Ranking in 1st, 2nd, 3rd
What is the outlier?
An extreme score that is unusually high or low in comparison with the rest of the scores in a sample.
What is a statistic based on the whole population; this is symbolized by a greek letter?
Parameter ( μ ) also seen as (mu) for the population mean
Define percentile.
The percentage of people who scored at or below a given raw score.
Name a circle graph with a slice for every category.
Pie chart
T/F: A population is of all the people, represented by a sample in a study, to whom we mean to generalize?
True
What is a distribution in which the peak is to the left of the mid point?
Positive skew
Conducting an experiment and insulting every participant in it has an equal chance of being assigned to any of the groups, or experimental conditions is known as….
Random assignment
Name the sample type if you are taking a sample in such a way that every member of the population has an equal chance of being selected in to the study..
Random Sample
What is a measure of variation calculated by subtracting the lowest score from the highest score in a distribution?
Range
What is the most sophisticated scale of measurement we use with order, equal units of measurement, and an absolute zero that indicates an absence of the variable being measured?
Ratio Scale — Common ratio scale is time
A data point that has not been transformed, analyzed, or change in any way is called what?
A raw score
A group of people who participate in a study is known as…
A sample
When the scores in a distribution pile up towards one end and the tail of the distribution goes off in the opposite direction… this is known as…
Skew… It can be either positive or negative.
Define standard deviation
- Study the abbreviation for this*
A measure of variation
The square root of the average squared deviation from the mean
This is the most commonly used measure of variation in psych and along with variance (standard deviation squared) is an integral part of many inferential stats.
How would you get the standard deviation if you had the variance?
Square the Standard Deviation
How would you find the standard deviation if you have the variance?
Square root the variance
What is a normal distribution with a mean of 0 and a standard deviation of 1?
Standard normal distribution
What are standard scores?
Raw score expressed on a standardized scale relative to the mean and standard deviation
Define ubiquity of the normal curve…
The concept that the bell-shaped curve describes the approximate shape of the distributions of a surprising number of characteristics that vary
What is a z-score?
A number that expresses how far a raw score is away from the mean in standard deviation units.
AKA standard score