Descriptive Statistics and Descriptive Research Flashcards
(38 cards)
What is the difference between continuous data and categorical data?
Continuous data involves using data with numeric values (Age, weight, height) while categorical data is used with categorical values (Gender, race, exposure/disease status).
Categorical data can be divided into ________ or __________. What is the difference?
- Nominal- Numerals are category labels
- Ordinal- Numbers indicate rank order
List these as categorical or continuous:
- Age
- Sex
- Race
- Education
- Language
- STOFHLA
- Age = continuous
- Sex = categorical
- Race = categorical
- Education = categorical
- Language = categorical
- STOFHLA = continuous
What 3 things do we do to describe continuous data?
- ) Check it’s distribution (symmetric, skew left, bimodal, multimodal)
- ) Measure its center
- ) Measure its spread
Draw a __________ to check the distribution of a continuous variable.
histogram
Normal distribution is a probability distribution that is:
- _________ about the center
- data near the center are more _________
- a ____ curve in graph form
- symmetric
- frequent
- bell
What are some non-normal distributions of data?
- Bimodal
- Skewed to the right
- Skewed to the left
- Multimodal
What are 3 ways to measure the data “center”? Which is the most common used for value of central tendency?
- mean (most common)
- median
- mode
When is median better than mean?
When there is an outlier or data is skewed.
For data distributed symmetrical -\_\_\_\_ = \_\_\_\_\_\_ = \_\_\_\_\_\_ For data distributed skewed to the right -\_\_\_\_\_ < \_\_\_\_\_\_ < \_\_\_\_\_ For data distributed skewed to the left -\_\_\_\_\_\_ < \_\_\_\_\_ < \_\_\_\_\_
For data distributed symmetrical - mean = median = mode For data distributed skewed to the right - mode < median < mean For data distributed skewed to the left - mean < median < mode
What are 3 ways to measure the data “spread”?
- Standard deviation (SD)
- Range
- Interquartile rnage (IQR)
- What is standard deviation?
- Standard deviation is the most common value for spread of the data around the _____.
- square root of {(sum of square of the deviance from the mean) / (total number of values – 1)}
- mean
- What is range?
- Range is the most common value for spread of the data around the _____.
- When can range be misleading?
- max-min
- median
- in data with an outlier
- What is IQR?
- What is meant by Q1,Q2,Q3?
- IQR measures better than range when the data has an ________.
-Q3-Q1
- Q1 = the value that occurs at the first quarter mark
- Q2 = the value that occurs at the second quarter mark = Median
- Q3 = the value that occurs at the third quarter mark
-outlier
- __% of data falls within 1 standard deviation.
- __% of data falls within 2 standard deviation.
- __% of data falls within 3 standard deviation.
- 68%
- 95%
- 99.7%
In a research study of 100 patients, their calcium levels were measured to range from 8.8 – 15mg/dL, with a mean of 12.1 mg/dL. The calcium levels fall in a Normal distribution, with a standard deviation of 1.0 mg/dL. Based on those reported measures, what is the approximate proportion of those whose calcium values are below 10.1?
- 1%
- 2.5%
- 5%
- 8.5%
- 16%
-2.5%
To describe categorical data you report _______ and __________.
- frequency-count the numbers in each category
- proportion-find the percent of each category
To visualize continuous data we use a ________ or a ________.
histogram or box plot
To visualize categorical data we use ____ or ______ graph.
pie or bar graph
Summary for Descriptive Statistics:
- Data level of measurement can be either _________ or ___________
- For a continuous data, its distribution can be visualized by drawing a histogram to check whether the data are distributed to be ________ or _______
- For a continuous data whose distribution is symmetric, ________ and ____________ are common to report
- For a continuous data whose distribution is skewed, _______ and ______________ are common to report
- For a categorical data, ______ and ________ are common to report to describe it
- To visualize the distribution of a continuous data, _______ may also be drawn as well as _______
- To visualize the distribution of a categorical data, _____ graph or ____ graph may be drawn
- continuous or categorical
- symmetric or skewed
- mean and standard deviation
- median and interquartile range (IQR)
- count and percent
- boxplot, histogram
- pie or bar
DESCRIPTIVE RESEARCH
DESCRIPTIVE RESEARCH
What are the 3 types of research?
- Descriptive
- Exploratory
- Explanatory
- Descriptive research is used to describe __________.
- Exploratory research is used to find ____________.
- Explanatory research is used to describe __________.
- populations
- relationships
- cause and effect
Exploratory and Explanatory are collectively called _______ research.
Correlational
