Need To Know- Test #1 Flashcards
Ch.1, Ch.2, Ch.3, & Ch.12 (70 cards)
Population (definition)
The complete collection of “all” individuals/items to be studied
Sample (definition)
A subcollection of members selected from the population
Parameter (definition)
A numerical measurement describing some characteristic of a population
Statistic (definition)
A numerical measurement describing some characteristic of a sample
Quantitative Data (or numerical data)
Data consisting of numbers representing counts or measurements
Discrete data (definition)
Quantitative data representing a finite or countable number
Continuous data (definition)
Quantitative data representing an infinite many possible values corresponding to some continuous scale that covers a range of values without gaps, interruptions, or jumps
Qualitative Data (or categorical data)
Data that consists of names or labels or numbers that do not represent a count of measurement
Simple Random Sample (SRS)
A sample of n subjects selected in such a way that every possible sample of size n has the same chance of being chosen. (i.e. choosing names out of a hat)
Systematic Sample
A sample in which the researcher selects some starting point and then selects ever nth element in the population (i.e. choosing every 3rd person, then every 5th person)
Stratified Sample
A sample in which the researcher subdivides the population into at least two different groups (or strata) and draws a sample from each group (i.e. separating into different grades, then choosing 50 from each group)
Cluster Sample
A sample in which the researcher first divides the population into sections (or clusters), and then randomly selects all members from some of those clusters (i.e. dividing into grades and choosing all of the freshmen and seniors)
Convenience Sample
A sample in which the researcher simply uses results that are very easy to get. (not a valid sampling method, results in biased data) (i.e. asking a random person walking by you the question)
Bias (definition)
If the results of the sample are not representative of the population
Sampling bias (definition)
The technique used to obtain the individuals to be in the sample tends to favor one part of the population over another
Nonresponse bias (definition)
When individuals selected to be in the sample who do not respond to a survey have different opinions from those who do
Response bias (definition)
When answers on a survey do not reflect the true feelings of the respondent
Which bias? To determine how TWU students feel about commuting, 100 TWU students were randomly chosen by selecting 50 men and 50 women to participate. They were asked how far they commute each day (in minutes) to campus
Sampling Bias
Which Bias? In a survey, subjects are asked to record how many alcoholic drinks they consume each day.
Response Bias
Which bias? A recent email poll asked teens whether they were using nicotine products. Only 10% of students responded. Of those, only 8% used nicotine products.
Nonresponse Bias
What is this symbol? ∑
Sigma
What does sigma mean?
Find the sum of all data points
What is this symbol? X
X
What does X mean?
A variable used to represent the individual data values
