A&A SL: Core Topics: Statistics Vocab

Lessons 11A - 11E Vocab

frequency histogram

• AKA: histogram

• similar to a column graph but the “columns“ are touching

• values at the edges of each column indicates class interval boundary

• used to represent continuous data

modal class

• the class with the highest frequency

• seen in both column graphs and histograms

class intervals

• when data has many different values with low frequencies it is useful to group the data

• then compare the frequencies of each class

• EX: *image is a way to group the frequencies*

group

• a way to categorize and organize data

outliers

• values that are much larger or smaller than the general data body

• appears separated on a column graph

• retained for analysis

• could be a data collection error and if so remove it from the data

positively skewed

• positive side is stretched

negatively skewed

• negative side is stretched

systemic

• systemic about the mode

mode

• most frequently occurring value

• highest column on a column graph

column graph

• displays simple data

• displays discrete data

• possible data on horizontal axis

• frequency of data on vertical axis

• column widths are equal

• height represents frequency

• gaps between data indicates discrete

relative frequency

• frequency divided by the total number of recorded values

• indicates proportion / population of results that take value

frequency

• column that summarizes the number of occurrences in each data value

tally

• used to count the number of 1s 2s 3s and so on

• read data left to right

• vertical stroke tally column

• represents 5 occurrences

quantitative continuous variable

• any numerical value in a certain range

• result of measuring

quantitative discrete variable

• exact numerical

• result of counting

numerical data

• all information collected

quantitative variable

• has numerical value

categorical data

• all collected information

categories

• what data is divided into

categorical value

• specific quality or characteristic

variable

• a part of data collection that is associated with the population

• will either be categorical or numerical

stratified / quota sampling

• when a population can be divided into subgroups

• when subgroups can be equally represented

• EX: a high school divided into grades

• stratified sample: individuals from each strata are selected

• quota sample: individuals specifically chosen by the interviewer

convenience sampling

• selecting a sample based on who is more accessible or more likely to respond

systematic sampling

• selecting members of a population at regular intervals

• useful when not all population members are available at the same time

simple random sampling

• each member of the population has the same chance of being selected for the sample

• each set of n members has the same chance of being selected as any other set of n members

• practical to number the members and randomly generate to select the sample

randomly select

• helps to prevent bias

• everyone has an equal chance at being selected

non-responded error

• lack of a response

• could be due to a variety of factors

coverage error

• sample does not reflect population

• proves that the sample needs to be large and unbiased

measurement error

• inaccuracies in measurement regarding data collection

• slight differences from actuality

• could be due to bad questions

census

• accurate way to study a population of interest

• understand that it is impossible to study the total population

sample

• the select group from a population

error

• when estimation is incorrect

sampling error

• characteristic of sample differs from total population

• random