Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
130 Cards in this Set
- Front
- Back
Are different types of variables analyzed differently?
|
Yes
|
|
What are the two ways that data is organized and displayed?
|
Numerically and Visually
|
|
How is data displayed numerically?
|
Through the use of tables.
|
|
How is data displayed visually?
|
Through the use of graphs and charts.
|
|
How many variables does a frequency table display?
|
One
|
|
This contains the number and percentage of people who gave each response?
|
Frequency Table
|
|
Does a frequeny table contain the number of people for whom no response are available?
|
Yes.
|
|
You can find the cumulative percentage of a variable here.
|
Frequency Table
|
|
This is one of the most convenient and useful ways of summarizing data numerically.
|
Frequency Table.
|
|
Do quantitative variables (ratio or interval; age, degrees) work well in a frequency table?
|
No
|
|
What types of variables work best in a frequency table?
|
Nominal and Ordinal (Categorical Variables)
|
|
What way(s) are best for displaying data visually when you are analyzing a categorical variable?
|
Pie charts and bar charts.
|
|
What way(s) are best for displaying data visually when you are analyzing a quantitative variable?
|
Histograms
|
|
This is a graphical display of counts for a range of data values for one variable.
|
Histogram
|
|
This axis displays the range of sample values for a variable of interest.
|
X-axis
|
|
This axis displays the count (or frequency) of observations within a range of values (height of bar determines frequency of values in that range)
|
Y-axis
|
|
In a bar chart, each bar stands for how many response choices?
|
One
|
|
In a histogram, each bar stands for how many response choices?
|
It varies - it represents a range
|
|
What kind of information can you get from a histogram that you cannot get from a pie chart or a bar chart?
|
1) Cluster around central value?
2) Outlying data points that are far removed from the rest? 3) Is distribution symmetrial or not (skewness)? |
|
If a skew exists to the right on a histogram, what is that also referred to as?
|
A positive skew.
|
|
If a skew exists to the left on a histogram, what is that also referred to as?
|
A negative skew.
|
|
For what type of variable would you use a pie chart?
|
Categorical Variable (nominal or ordinal)
|
|
For what type of variable would you use a bar chart?
|
Categorical Variable (nominal or ordinal)
|
|
For what type of variable would you use a historgram?
|
Quantitative (ratio or interval)
|
|
A frequency table can show us what two pieces of information that assists us in understanding quantitative variables?
|
1) Measures of central tendency
2) Measures of variability |
|
What are the 3 measures of central tendency?
|
1) Mean
2) Median 3) Mode |
|
Are the measures of central tendency (mean, median, and mode) computed using invalid responses as well as valid?
|
No.
|
|
This is the average value of all valid observations.
|
Mean.
|
|
This is the mid-point of all valid observations.
|
Median.
|
|
This is the most occuring valid observation.
|
Mode.
|
|
Where are the three measures of central tendency computed?
|
In the statistics box, that can be computed alongside a frequency table.
|
|
Are measures of central tendency helpful with categorical variables.
|
No.
|
|
How is range computed?
|
Largest - smallest value
|
|
This determines how spread out the values are. If all the cases were the same, the _______ would equal zero.
|
Variance.
|
|
What is the equation for VARIANCE?
|
Sum of squared distances from the mean for all cases / number of cases - 1
(value - mean)squared + (value - mean)squared / number of cases - 1 |
|
This is the square root of variance and is used to obtain a measure in the same units as the original data?
|
Standard Deviation.
|
|
How do you calculate standard deviation?
|
Square root of variance.
|
|
This is an expression of the standard deviation as a percentage of the mean. It allows for the comparison of variability of diferent variables.
|
Coefficient of variation.
|
|
How do you calculate coefficient of variation?
|
Standard Deviation / Mean X 100
|
|
This is used to determine the position of a case in the distribution of observed values.
|
Zscore or standard score
|
|
This tells us how many standard deviation units a case is above or below the mean.
|
Zscore or standard score.
|
|
How do you calculate Zscore?
|
value - mean / standard deviation.
|
|
If a value is in the 10th percentile, what does that mean?
|
That 10% of cases are smaller than your value.
|
|
The ____________ range is often used to show variability in data.
|
Interquartile
|
|
True or false: the interquartile range is often affected by outliers?
|
False
|
|
The 50th percentile is also referred to as what?
|
The median.
|
|
For most quantitative variables, which four characterstics tned to be of the most interest?
|
1) Location (center, average - mode, median, and mean)
2) Spread (variability, range, quartiles, variance, standard deviation). 3) Shape (standard deviation) 4) Outliers |
|
A way to visually display measures of central tendency and dipersion (variability) in viewing quantiative variables (2 or more groups).
|
Box plot
|
|
This visually represents all individual data values
|
Stem and Leaf plot
|
|
What values do box plots and histograms both show?
|
1) Median
2) Interquartile Range 3) Largest value 4) Smallest value |
|
T/F - the length of the whiskers is determined by the size fo the box?
|
True
|
|
How long are the whiskers on a box plot?
|
up to 1.5 box length from each edge of the box.
|
|
How far can an outlier exist visually from a box on a boxplot?
|
1.5 to 3.0 box lengths from the edges of a box
|
|
On a boxplot, how can you identify central tendency?
|
The line - the median.
|
|
How is an outlier identified on a boxplot?
|
an O
|
|
How is an extreme value identified on a boxplot?
|
a *
|
|
How far from the box is an extreme value on a boxplot?
|
over 3 box lengths from the box.
|
|
How can you identify how large your box is on a boxplot?
|
It is your interquartile range - 25% - 75%
|
|
Does the width of a box plot mean anything?
|
No.
|
|
This is similar to a histogram because it shows how many cases have various values - but differs becuase it preserves more information about values of oberservation.
|
A Stem and Leaf Plot
|
|
This looks like a histogram turned sideways.
|
Stem and Leaf Plot.
|
|
Stem width in a stem-and-leaf plot represents what?
|
How far to move the decimal.
|
|
If (Each leaf: 5) then...
|
Each leaf represents 5 cases.
|
|
This is used to numerically dispaly the comparison of the mean (averages) of one quantitative and one or more categorical variables
|
Compare Means
|
|
An explanatory variable in compare means is also called what?
|
Independent Variable
|
|
A response variable in compare means is also called what?
|
Dependent Variable
|
|
Which is dependent and independent: income and degree.
|
Income: dependent
Degree: Independent |
|
In SPSS, is the independent variable categorical or quantitative?
|
Categorical
|
|
In SPSS, is the dependent variable categorical or quantitative?
|
Quantitative
|
|
This allows you to visually see how two diferent independent variables are related to a dependent variable (two categorical, one quantitative)
|
Clustered Bar Chart
|
|
True or False: one variable in compare means is awlays a quantitative variable?
|
True
|
|
True or False: Boxplots graphically display a quantitative variable.
|
True.
|
|
This is a table that contains counts of the number of times various combinations of values of two categorical variables occur.
|
Crosstab
|
|
Can quantitative variables be analyzed using a crosstab?
|
No.
|
|
Which variable (dependent or independent) is usually the variable on the top of a crosstab?
|
Independent
|
|
Columns are usually made up of which variable (dependent or independent)?
|
Independent
|
|
This is the best way to visually display 2 categorical variables.
|
Stacked Bar Chart
|
|
This graphically displays two quantitative variables.
|
Scatterplot
|
|
This graphically displays three or more quantitative variables.
|
Scatterplot matrix
|
|
This numerically displays two or more quantitative variables.
|
Table of descriptive statistics
|
|
Which variable is usually plotted on the x-axis on a scatterplot?
|
Independent variable.
|
|
Which variable is usually plotted on the y-axis on a scatterplot?
|
Dependent variable.
|
|
Markers in a scatterplot allow us to add what type of variable?
|
Categorical.
|
|
Can SPSS create a line in a scatterplot? If so, what is it called?
|
Yes, a FIT LINE.
|
|
This is a characteristic of a sample.
|
Statistic.
|
|
This is a characteristic of a population.
|
Parameter.
|
|
The mean of a sample is demonstrated with what character.
|
_
x |
|
The standard deviation of a sample is demonstrated with what character.
|
s
|
|
The mean of a population is demonstrated with what character.
|
u
|
|
The standard deviation of a population is demonstrated with what character.
|
o/a
|
|
T/F = a normal distribution is symmetric and bell-shaped.
|
True
|
|
Where is the mean, median and mode on a curve of a normal distribution?
|
In the middle
|
|
How do the mean, median and mode relate to each other in a normal distribution?
|
They are equal.
|
|
Using the empirical rule, what percentage of values fall within 1 standard deviation of the mean in either direction?
|
68%
|
|
Using the empirical rule, what percentage of values fall within 2 standard deviations of the mean in either direction?
|
95%
|
|
Using the empirical rule, what percentage of values fall within 3 standard deviations of the mean in either direction?
|
99.7%
|
|
What is another name for a standardized score?
|
Z-score
|
|
This measures how many standard deviations the value (or raw score) falls above or below the mean
|
Z-score
|
|
How do you calculate Z score?
|
value - mean / standard deviation
|
|
T/F : every value has a z score?
|
True
|
|
What is the z-score for the mean of a normally distributed curve?
|
0
|
|
In a normally distributed curve, what percentage of the time does an 'unusual' event occur?
|
5% of the time
|
|
5% of the observations fall outside the range of what z-scores?
|
2 and -2
|
|
What is the p value of an unusual or statistically significant observation?
|
0.05
|
|
Using sample information to make conclusions about a broader range of individuals than just those who are observed is called what?
|
Inferential statistics
|
|
T/F: inference methods can only be applied when it is reasonable to assume that the data are representative for the question being considered about a larger group.
|
T
|
|
How does one guarantee that the sample is representative of the larger population?
|
Take a random sample
|
|
These are numerical values computed from a sample (such as mean, standard deviation, proportion of observations that fall in a particular category)
|
Statistic
|
|
These are numbers associated with a population (fixed, unchanging numbers such as "normal" body temperatures = 98.6, "average work week - 40 hours)
|
Parameter
|
|
This is defined as the distribution of all possible outcomes for a statistic (within samples of the same size)
|
Sampling Distribution
|
|
The standard deviation of the sampling distribution is called what? (for example, the standard deviation of all possible values of a sample mea)
|
Standard Error
|
|
This refers to the variability of the observations in a sample
|
Standard Deviation
|
|
This refers to the variability of a statistic
|
Standard Error
|
|
By using a histogram to evaluate a distribution of means, you would be looking at what?
|
Sampling Distribution
|
|
By computing descriptive statistics for a group of means, you would be able to calculate the standard deviations of the means which is called what?
|
Standard Error
|
|
How do you calculate the standard error of the mean?
|
population standard deviation / square root of sample size in your group (o / square root of n)
|
|
T/F: larger samples show less variability in the possible outcomes?
|
True
|
|
How do you calculate a z-score or standard score for an observed mean?
|
Value - population mean / standard error of the mean
|
|
This visually displays the interquartile range?
|
Stem and Leaf Plot
|
|
How can you visually display the distribution of z scores as it applies to the empirical rule?
|
By using a Z score histogram
|
|
Best option for numerically displaying the number of cases who gave each response for ONE variable.
|
Frequency Table
|
|
Used for graphically displaying the number of cases who gave each response for ONE variable.
|
Pie Chart
Simple Bar Chart Histogram Box Plot Stem and Leaf Plot |
|
Best option for numerically viewing the averages of ONE quantitative variable across categories of ONE qualitative variable
|
Compare Means
|
|
Best choice for graphically displaying the averages of ONE quantitative variable across categories of ONE qualitative variable.
|
Simple Bar Chart
|
|
Best option for numerically viewing the averages of ONE quantitative variable across categories of TWO qualitative variables.
|
Compare Means
|
|
Best choice for graphically displaying the averages of ONE quantitative variable across categories of TWO qualitative variables.
|
Clustered Bar Chart
|
|
Best option for numerically viewing the relationship between two categorical variables. In other words, this shows the counts of cases in each response category of one categorical variable across response categories of another categorical variable.
|
Crosstab
|
|
Best choice for graphically displaying the relationship between two categorical variables.
|
Stacked Bar Chart
|
|
Best option for numerically viewing the relationship between two quantitative variables?
|
Tables of descriptive statistics
|
|
Best option for graphically viewing the relationship between two quantitative variables?
|
Scatterplot
|