Chapter 1 Flashcards
xWhat is a population?
Basically the entire group
What is a sample?
Subset or part of a population to represent a population the sample is drawn from
What is a sample represented by?
Data derived from observations, outcomes, responses, measurements, or counts (scores)
A survey is conducted of all residents of an apartment building
to determine the average family size of all residents. The residents
represent a ________.
Population
All residents of an apartment building are surveyed to determine average annual income. The data are used to estimate average household income for people living in that neighborhood. The people surveyed represent a ________.
Sample
What is a parameter?
Numerical description of a measurable population characteristic
What is a statistic?
Numerical description of a sample characteristic
What does a parameter provide information on?
Whole population
A numerical measure that describes a sample characteristic is a ________.
Statistic
A numerical measure that describes an entire group of people or things is a ________.
Parameter
The average GPA of thirty students from a large community college having coffee at the student union is a ________.
Statistic
What are descriptive statistics?
Involve the organization, summarization, and display of data
What are descriptive statistics used for?
To present quantitative descriptions in a manageable form
What does descriptive statistics help us with?
Simplify large amounts of data into easier parts
What is the downside of descriptive statistics?
Basically you don’t know the why, just the data
What are inferential statistics?
Drawing conclusions about a population based on data from a collected sample (conclusions extend beyond data in hand)
What is the difference between inferential and descriptive statistics?
Inferential is generalizations about things we can’t directly measure, descriptive stats describe data we have collected
When do researchers use inferential statistics?
When it is not convenient, or possible to look at the whole population
Graduating high school seniors are ranked according to their grade averages?
Descriptive
A survey concludes that most students favor using e-books for texts.
Descriptive
Batting averages of ballplayers are posted online.
Inferential
A researcher reports that 90% of college students text during class.
Inferential
What is quantitative data?
Information about qualities
What does quantitative data tell us?
How much, or how many of something are presented as sets of numbers
What types of data is quantitative data?
Either continuous or discrete
What is continuous data?
Can theoretically take on any value within a specific range, can be measured and tells us how much
What is discrete data?
Can only take on certain values, gaps between values, can be counted and tells us how many
What is qualitative data?
Names or categories, observed but not measured, cannot be operated mathematically
What types of data is qualitative data?
Descriptive only
What are examples of quantitative discrete?
Score of a rugby match, number of siblings, rooms
What are examples of quantitative continuous?
Distance between cities, cost of groceries, annual income
What are examples of qualitative data?
Make of automobile, city of residence, postal code
What is GPA?
Quantitative continuous
What is grade point average as letter grades?
Qualitative (categories)
Computer operating system designation
Qualitative
Annual salary of professors at the university
Quantitative discrete
Number of correct answers on a chemistry exam
Quantitative continuous
What is nominal data only?
Qualitative (only based on names, labels, or qualities)
What measures of quantity can ordinal data be?
Either quantitative or qualitative and can be ordered or ranked into discrete groups
What is statistics?
Science of classifying, organizing, and analyzing data
What is data?
It could be anything
What is information from samples?
Statistics
What is information from populations?
Parameters
What do we make inferences on?
Populations
What is random sampling?
Procedures that ensure all samples of a particular size have an equal chance of being selected
What are mutually exclusive observations?
Each observation has only one appropriate category
What are exhaustive observations?
All observations fit somewhere
What are the four levels of measurement?
Nominal, ordinal, interval, ratio
What is nominal data?
Represent categories with only qualitative differences
What is nominal data always?
Mode.
What are examples of nominal data?
Eye color, tv brand
What is ordinal data?
Rank ordered on some dimension, quantitative (more or less than)
What does ordinal measurement not guarantee?
Equal distance between rankings
What are interval scales?
Maintain equal distance between the categories
What are the details of the interval scale?
Differences are comparable on different parts of the scale, but we can’t speak in terms of proportions on that scale
What are ratio scales?
Allow us to express data in terms of proportions
What is the difference between ratio and interval scales?
Ratio scales contain a true zero
What are examples of ratio scales?
Length of TV in inches, and # of months until first repair
What are additional properties of ratio scales?
Interval and ratio scales have equal spaces between categories, so you can manipulate the scale values, but still maintain the relationship
When can variables only be measured?
At discrete units, in order to measure
What is a statistical question?
Questions about the numbers representing the observations
What are non-experimental designs?
Correlational, observational
What are experimental designs?
Independent and dependent variables
What is the first step of a study design?
Identify the population to which you want to apply results, and how you could get a sample from this
What is the second step of a study design?
Identify any IV and DV and how they will be measured
What is the third step of a study design?
Identify scale of measurement for your variables
What is a statistical conclusion?
A conclusion about numerical properties of the data
What is inferential procedure?
A test
What is a research conclusion?
Includes assessments of the research methods
What are nominal data categories?
Mutually exclusive, all must be sorted into one or another category with no overlap
What can numbers be used as?
Labels but no additional meaning or operability
What data set are interval data?
Quantitative,
What is with the ordinal data?
Distance between data is not meaningful
What can the data in an ordinal scale indicate?
Higher or lower or more than or less than, with respect to a value or characteristic
What does it mean in an interval scale that the data is meaningful?
Values can be added and subtracted and averages calculated but not ratios, since there is no absolute zero point
In an interval scale what does the zero mean?
Represents a point on a scale and not an inherent zero
What are examples of interval data?
Scores on a standardized IQ test, temperature shown on a scale
What does the zero in ratio data mean?
That the ratio of two data points can be expressed as a multiple of another data point
What can ratio levels be?
Added, subtracted, multiplied, and divided
What are examples of ratio data?
Height and weight, numerical scores on an exam
What is a variable?
Something can can change or be changed, represents different values in an equation
What are levels?
Not many parts
What are scores?
A variable that can divided into many parts, what the parts are called
What is step 1 in a statistical study?
Identify population of interest
What is step 2?
Develop a detailed plan for collecting data
What is step 3 statistical study?
Collect the data
What is step 4?
Describe the data using descriptive statistics
What is step 5?
Interpret the data and make decisions about population using inferential statistics
What is step 6 to a study design?
Identify any possible errors and make recommendations
What does an experimental study support?
Claims of cause and effect
What scenario do experimental studies typically involve?
Treatment, procedure, or program is intentionally introduced and a result is observed
What is an experimental study in simple terms?
Researcher applies treatments to participants, records the results and compares to those that got the treatment and those that did not
Which study involves active manipulation?
Experimental
Which study involves passive manipulation?
Observational
What is a simulation?
Modeling random events so that simulated outcomes closely match real-world ones
What is the difference between a survey and an observational study?
Survey requires interaction with the participants
What is validity?
How accurate the study is
What is reliability?
Consistency of results over time and trials that can be established by replicating the results
What is replication?
Repeating an experiment with different participants to confirm results
What is a statistical conclusion in essence?
After applying an inferential procedure, we make statistical conclusions about the data
