Descriptive Statistics Flashcards
Descriptive Statistics
The branch of statistics that focuses on the presentation of data
Inferential Statistics
The branch of statistics that deals with analyses and conclusions beyond the data
Mean
This is synonymous with the word “average”.
Law of Large Numbers
it says that as we increase the number of trials (or samples taken), we expect that the results from all these trials (𝑿̅) should be close to the expected value (𝝁).
Median
It is the point or value that splits our data into two equal subgroups
Mode
is simply the value that appears the most in your data set
Precision
values are less dispersed
Accuracy
refers to how close we are to the actual values.
Range
is the simplest measure of variation for our data set. It is just the difference of the largest value and the smallest value.
Variance
is the average of the squared deviations from the mean. It is usually given the symbol σ^2 = [∑(𝑥 − µ)^2]/N
Deviations
how far each of the data points are away from the mean (x - µ)
Sample variance
𝑠^2 = [∑(𝑥 − 𝑥̅)^2]/(n - 1)
Standard deviation
is an extension of the variance where we fix the problem of having squared units for the variance.
Non-probability sampling
is one which the sample individuals are not selected randomly. Some population individuals have a higher likelihood of being selected than others.
Convenience Sampling
is a type of non-probability sampling in which people are sampled simply because they are “convenient” sources of data for researchers.
Voluntary Response Sampling
is a type of non-probability sampling in which the respondents voluntarily elects themselves to be included in the sample.
Purposive Sampling
is a type of non-probability sampling in which respondents are selected based on their knowledge, ability or skill to participate and contribute in the given study.
Snowball Sampling
is a type of non-probability sampling in which the respondents are asked to assist the researchers in identifying other potential subjects.
Bias
is any trend or deviation from the truth in data collection, data analysis, interpretation and publication which can cause false conclusions.
Selection Bias
occurs when individuals or groups in a study differ systematically from the population of interest leading to a systematic error in an association or outcome.
Confirmation Bias
occurs when there is a tendency to process information by looking for, or interpreting, information that is consistent with one’s existing beliefs
Survivorship Bias
a type of selection bias where the results, or survivors, of a particular outcome are disproportionately evaluated.
