Content Strand 4: Probability and Statistics - Item Specification (8-2005)

PS02 (Data Collection and Central Tendencies) Describe how a question, collection method, and/or population may affect the data collected; determine and use range and measures of central tendency to describe or interpret a set of data (1.4.3, 1.4.4)

Item Format:

· Multiple-Choice and Short-Answer items may be used to test this learning target.

Stimulus, Stem, and Prompt Rules:

· Stimulus may include descriptive scenarios that involve survey questions, collection methods, and population.
· Stimulus may include table, charts, diagrams, pictures, scatter plots, stem-and-leaf plots, and box-and-whisker plots.

Mathematical Vocabulary and Terms:

· Terms that may be used: data, mean, median, mode, population, questionnaire, range, sample, survey
· Terms that may be used with definitions or examples: bias, variable
· Terms that may not be used: measures of central tendency, reliability

Item Characteristics:

a) Items may ask students to identify or write survey questions that will obtain the appropriate information and will avoid bias.
b) Items may ask students to identify or describe how to collect data about a given population, taking into account issues such as the question, collection method, and sample population.
c) Items may ask students to describe how a question, data collection method, or population may affect the data.
d) Items may ask students to identify, determine, and/or use mean, median, mode, and range as appropriate to describe a set of data.
e) Items may ask students to explain the difference between mean, median, and/or mode as a measure of central tendency in a given situation.
f) Items may ask students to explain or determine how data added to a data set may affect the mean, median, mode, and/or range of the data.
g) Items may ask students to complete a set of data based on a given mean, median, or mode and a partial set of data.