Statistics Primer Flashcards
What is a population?
Every member with a selected characteristic
What is a sample?
Subset of given sample which represents the population
What graph is used to plot two continuous variables?
Scatter plot
Independent variable on the x axis
Dependent variable on the y-axis - what we measure
What graph is used for then comparing two or more groups for a single measurement?
The box plot
How can tables be modified so that you can see compare samples?
Can be cross-tabulated
What are variables?
These are any parameters that can be measured
What are variates?
This is a quantity which may take any of the values of a specified set with a specified relative frequency or probability
What is qualitative data?
Nominal scale - categories (e.g. positive/negative)
What is ranked data?
Ordinal scale - sequenced order ( they are relative to each other)
What is quantitative data?
Numbers that produce a various scale
What is discontinuous data?
Discrete scale - obtained by counting integers ( whole numbers)
What is continuous data?
Obtained by measuring - there can be decimal places
What is derived data?
Calculated from direct measurements - ratios, percentages etc.
Nominal and Ordinal Example:
This should be named and have directionality
Statement: I m excited to be learning about statistics
Answer options: strongly agree, disagree, neither/nor agree, agree, strongly agree
Discontinuous quantitative example:
Number of carbon atoms in molecule - integer and numerical
Continuous quantitative example
Mass of chemical compound, weighed on a balance
Absorbance, measured using a spectrophotometer
Grey areas
Shoe size - ranked data?
Age of students - can be discontinuous if only taken in years ( integers) or can be continuous if time/days/months are taken into consideration
Define accuracy
The closeness of measurements to true value
Define precision
Closeness of measurements to true value
What is bias?
This is the deviation of measured values from the true value - systematic/consistent
What is variability?
This is imprecision in repeated measurements
What is range?
The difference between the largest and smallest values
Problem - don’t know about the values within the range - number or values of them
