Statistics Vocabulary List – Flashcards

Unlock all answers in this set

Unlock answers
question
1st Quartile*
answer
25th percentile of the observation below it
question
2nd Quartile
answer
50th percentile of a data set, the Median
question
3rd Quartile
answer
75th percentiles of a data set
question
68-95-99.7 Rule*
answer
In all score-based normal curves, 50% of the scores fall at or above the mean and 50% at or below the mean. (Approximately 68% of all scores fall within one standard deviation of the mean, 95% within two standard deviations, and 99.7% within three standard deviations)
question
Actual Sample*
answer
Part of the population from which we actually collect information
question
Alpha
answer
Known as SIZE or TYPE-1 ERROR. Type 1 Error: isn't fine but found out was Fine, error that doesn't cost lives
question
Bar Graph*
answer
Graph of the distribution of a categorical variable; can compare any set of quantities measured in the same unitused with the categorical data to compare the sizes of categories.
question
Bias*
answer
If the design of a statistical study symmetrically favors certain outcomes
question
BoxPlot*
answer
Based on the 5-number summary of a data set. Each value in the 5-number summary is located over its corresponding value on a number line.
question
Categorical Variable (qualitative)
answer
Any variable that is not quantitative is categorical. Categorical variables have no numerical meaning. Examples: Hair color, gender, field of study
question
Chi-square*
answer
Method for testing the association between the row and column variables in a two-way table. Used to determine whether there is a significant difference between the expected frequencies and the observed frequencies in one or more categories.
question
Coefficient of Determination
answer
Assess how well a model explains and predicts future outcomes
question
Complement*
answer
Is the opposite of the probability of something happening. of an event is the event not occurring.Given the probability of an event, the probability of its complement can be found by subtracting the given probability from 1. The set of all outcomes in the sample space that are not included in the outcomes of event A.
question
Control Group*
answer
A group that does not receive the treatment
question
Convenience Sample*
answer
A sample where the subject are selected, in part or in whole, at the ease of the researcher. A statistical method of drawing representative data by selecting people because of the ease of their volunteering or selecting units b/c of their availability or easy access.
question
Correlation*
answer
Measure the direction and strength of the linear association between two quantitative variable (x and y) Possible correlations range from +1 to -1. A zero correlation indicates that there is no relationship between the variables. A correlation of -1 indicates a perfect negative correlation, meaning that as one variable goes up, the other goes down. A correlation of +1 indicates a perfect positive correlation, meaning that both variables move in the same direction together
question
Cut Point for Outliers
answer
The conventional cut-off point is 4/n
question
Disjoint*
answer
When two events share no common outcomes. To separate or disconnect the joints or joining of; no outcomes
question
Double Blind*
answer
Neither the experimenters nor the participants know which participants are in the experimental and control groups.
question
Exhaustive
answer
When a set of events comprises all possible occurrences of a reference set
question
Expected Value
answer
The counts we would expect -except for random variation-if the H0 were true
question
Experiment*
answer
imposes some treatment on individuals in order to observe their responses
question
Explanatory variable*
answer
x-value Variable that explains or causes changes in the response variable. The independent x variable
question
Form, Direction, Strength, outlier*
answer
Form, Direction, Strength, outlier are information that describes Scatterplots Form - If there is a straight line (linear) relationship, it will appear as a cloud or swarm of points stretched out in a generally consistent, straight form Direction- Positive or negative association on graph, Strength - How close the points in the scatterplot lie to a simple form such as a line. Outlier - is an observation that lies an abnormal distance from other values in a random sample from a population, points that do not follow the pattern.
question
Histogram*
answer
a graph that shows quantitative numbers where the bar touches. Shows how frequently data occur within certain ranges or intervals. The height of each bar gives the frequency in the respective interval.
question
Independent*
answer
There is a no relationship between the two categorical variables that is in the rows
question
Interquartile range
answer
distance between the first and third quartiles, aka the distance between the 75th percentile and the 25th percentile.
question
Matched Pairs
answer
The design of an experiment for paired comparison in which the assignment of subjects to treatment or control.
question
Mean
answer
the average of a set of data (sum of values divided by # of values)
question
Median
answer
The middle score of a distribution
question
Mode*
answer
Most frequently occurring number
question
Mutually Exclusive
answer
Two events cannot both cannot happen/Two events are mutually exclusive (or disjoint) if it is impossible for them to occur together.
question
Negatively Associated
answer
A relationship in paired data in which one variable's values tend to increase when the other decreases, and vice-versa.
question
Normal Distribution
answer
The normal (or Gaussian) distribution is a family of bell-shaped, symmetric density curve
question
Non-Response Bias
answer
Occurs in statistical surveys if the answers of respondents differ from the potential answers of those who did not answer.
question
Observational Study
answer
Observe individuals and measures variable of interest but does not attempt to influence the responses.
question
Observed value
answer
Values that are given; what is seen.
question
One Tailed Test
answer
The alternative hypothesis states that the parameter is larger than or smaller than the null hypothesis value
question
Outlier
answer
An observation that is numerically distant from the rest of the data. an individual value that falls outside the overall pattern of the relationship
question
P value
answer
A probability, with a value ranging from zero to one
question
Parameter
answer
A numerical quantity measuring some aspect of a population of scores.
question
Placebo
answer
A simulated treatment for a condition/study intended to deceive the recipient
question
Population
answer
The entire group of individuals about which we want information from.
question
Positively Associated
answer
When the scatter plot gives you a positive slope
question
Quantitative variable
answer
They represent a measurable quantity
question
Questionnaire Bias
answer
The way a question is asked to influence the response of the person
question
Randomize
answer
Subjects are selected randomly
question
Regression Line
answer
A straight line that describes how a response variable y changes as an explanatory variable x changes.
question
Residual
answer
Difference between the actual and estimated function value. difference between an observed value of the response variable and the value predicted by the regression line
question
Residual Plot
answer
Is a scatterplot of the regression residuals against the explanatory variable.
question
Response Variable*
answer
A variable you are predicting from (dependent y value)
question
Sample of Interest*
answer
everyone you sample and hope will respond
question
ScatterPlot*
answer
Graph of the two quantitative variables measured on the same individuals. summary of a set of data that shows the realtionship between two variables.
question
Shape, Center and Spread*
answer
Is the way to describe the overall pattern of a histogram.
question
Simple Random Sample*
answer
Each individual in the population has the same chance of being chosen for the sample
question
Skewed *
answer
A distribution is not symmetric; they are not mirror images of each other
question
Skewed to the Left
answer
A distribution is one in which the tail is on the left side
question
Skewed to the Right
answer
A distribution is one in which the tail is on the right side
question
Square of the Correlation*r²
answer
It is has a value that ranges from zero to one, and is the fraction of the variance in the two variables that is shared. r², is a useful value in linear regression.
question
Standard Deviation*
answer
Measures the spread by looking at how far the observations are from the mean; also the square root of the variance. s is zero when there is no spread and gets larger as the spread increases; square-root of the variance s squared
question
Standard Normal Deviation*
answer
Has a mean of 0 and a standard deviation of 1
question
Statistic*
answer
A numerical measurement describing some characteristic of a sample. The science of collecting, analyzing, and interpreting data. "Methods used to summarize, analyze, or make inferences from data" a number that can be computed from the sample data without making use of any unknown parameters
question
Stratified Random Sample
answer
A sampling design in which the population is divided into several sub-populations, and random samples are then drawn from each stratum
question
Strength*
answer
a scatterplot shows an association that is this if there is little scatters around the underlying relationship. how close the points in the scatterplot low to a simple form such as a line
question
Treatment*
answer
The intervention or other controlled circumstance applied to randomly assign experimental units. Any specific experimental condition applied to the subjects
question
Two-Tailed Test
answer
Either tail of the distribution (positive or negative) will lead to the rejection of the null hypothesis of no difference. the alternative hypothesis states that the parameter is different from the null value
question
Undercoverage*
answer
Occurs when some groups in the population are left out of the process of choosing the sample. A bias sample in a way that gives a part of the population less representation than it has in the population.
question
Variance
answer
The sum of squared deviations from the mean, divided by the count minus one
question
Voluntary Response Bias*
answer
Occurs when sample members are self-selected volunteers, as in voluntary samples
question
Z-Score*
answer
Gives the number of how many standard deviations x lies from the distribution mean. Tells how a single data point compares to normal data. Tells you not only whether a point was above or below average, but how unusual the measurement is.
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New