distributions Flashcards
What type of plot is used to show the distribution of continuous variables?
A histogram is used to visualize the distribution of continuous variables. While “siblings” might be plotted with a histogram, it’s technically not one since the data is discrete, but the concept remains useful.
What type of plot is used for summarizing counts of categories?
A bar chart is used to represent the frequency or count of different categories, where each category is shown as a separate bar.
When should you use density plots?
Density plots are used to describe the shape or distribution of continuous data, showing how data points are distributed across values. They should not be used for categorical data.
What is the advantage of using tables over figures?
Tables provide exact values and percentages, which offer precise information for comparison, whereas figures give a more visual representation, which might not be as detailed.
What is a potential disadvantage of using tables?
Tables can become overwhelming if there are too many categories (typically more than 5), which can make interpretation difficult.
How many categories is too many for a table?
10 or more categories in a table is typically too many. It may be better to use a graph or group categories to make the data easier to interpret.
How can categories in a table be managed if there are too many?
Categories can be combined into broader groups to make the table more manageable, but this may lead to a loss of detailed information.
What is the difference between population and sample distributions?
A population distribution shows the frequency of values in the entire population, while a sample distribution shows the frequency of values in a subset (sample) taken from that population.
How does sample size affect the resemblance between sample and population distributions?
Larger samples tend to resemble the population distribution more closely, while smaller samples may not accurately reflect the population’s characteristics.
What are unimodal distributions?
Unimodal distributions have one peak (mode) and can be symmetrical (even distribution of values on both sides of the peak) or asymmetrical (skewed to one side).
What is a bimodal distribution?
A bimodal distribution has two peaks (modes), indicating two common values or ranges in the data. It can suggest two different groups within the data.
What is a uniform distribution?
A uniform distribution has no peaks, with all values having an equal probability of occurring. The data is evenly distributed across all values.
What is skewness in a distribution?
Skewness measures the asymmetry of a distribution. A skewed distribution is not symmetrical, with one tail being longer than the other.
What does a positive skew indicate?
Positive skew means the distribution is right-skewed, with a longer tail on the right. It typically occurs when there’s a lower limit on the variable (e.g., reaction times).
What does a negative skew indicate?
Negative skew means the distribution is left-skewed, with a longer tail on the left. This often happens when there’s an upper limit on the variable (e.g., scores on an easy exam).
