Data About Us
Standards & Objectives | |
File Size: | 258 kb |
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Goals for Data About Us
Students should...
- Understand and use the process of statistical investigation
- Distinguish data and data types
- Display data with multiple representations
- Recognize that a single number may be used to characterize the center of a distribution of data and the degree of variability (or spread)
Investigation 1
Vocabulary | |
File Size: | 154 kb |
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Investigation 1 presents introductory statistical material that will be used throughout Data About Us. It focuses on describing, interpreting, and comparing distributions of data. It is intended both as a pre-assessment of what students might already know and as a way to build understanding related to foundations of data analysis. Students are introduced to the process of statistical investigation. They also review and/or develop background in working with frequency tables, line plots, and bar graphs. Anticipating and recognizing how data vary are two key components of data analysis introduced in this Investigation. Selected measures of center (median and mode) and variability or spread (range) are explored.
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Investigation 2
Vocabulary | |
File Size: | 156 kb |
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This Investigation focuses on developing the concept of mean. The average number of people in students’ households provides the setting. The notion of “evening out” the distribution at a point (the mean) located on the horizontal axis is modeled by using cubes, ordered-value bar graphs, and line plots. The models support development of an algorithm for finding the mean: adding up all of the numbers and dividing by the total number of numbers. Students distinguish between categorical data and numerical data. They also make connections between data types and choice of measures of center and variability (or spread).
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Investigation 3
Vocabulary | |
File Size: | 158 kb |
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Investigation 3 focuses on two measures of variability: interquartile range (IQR) and mean absolute deviation (MAD). Students are introduced to the IQR in the context of deciding how well a group of students estimate cereal portions for two different cereals. Students apply their knowledge of the IQR as a tool to analyze a database of cereals (70) and their sugar content. Finally, students are introduced to the MAD as a way to describe the differences in variation in wait times at an amusement park.
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Investigation 4
Vocabulary | |
File Size: | 158 kb |
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In Investigation 4, students extend their skills in working with data by comparing data sets using measures of center and spread. Students compare two or more distributions by looking at outliers (a new concept), how data vary, and which measures of center are appropriate to use as comparisons.Students begin to notice that representations such as line plots and bar graphs are not suitable for displaying some data sets; larger patterns within the data sets can only be seen when the data are grouped. Additionally, it is time consuming to graph individual cases of data sets when the sets are so large.
Students learn to construct and analyze histograms and box-and-whisker plots in this Investigation. Box-and-whisker plots and histograms are representational tools that permit grouping data in intervals. They are more efficient and allow for more patterns to be seen when working with large data sets. In box-and-whisker plots, the data are grouped into four quartiles, each of which includes one fourth of the data values. In histograms, students can choose which interval size to use; the interval size remains constant throughout the graph. |