Data Analysis

What is the Data Analysis tool?

The Data Analysis tool lets students handle data sheets and graphs. Use Data Analysis to practice working with data sets or with samples from probability distributions.

Note

Data Analysis does not automatically evaluate student input. The tool is intended for data investigation, not for answering a question. If you want an exercise that involves data analysis that our system can check, combine the Data Analysis tool with a question using a question type such as Multistep, Fill in the Blanks or Multiple Choice.

There are two main uses for the data analysis tool:

  • Allowing students to work with larger datasets.
  • Displaying charts and plots to support other exercises.

Creating a Data Analysis interaction

To create a Data Analysis interaction, you need to enter data for students to work with. There are four ways to enter data into the Data Analysis tool:

  • Sampling data based on distribution settings.
  • Uploading a CSV dataset.
  • Creating a local dataset.
  • Letting students upload their own dataset.
Note

If you are creating multiple Data Analysis interactions, you can reuse the same data source across them. If you select an existing data source, you must choose if you want this data source to be linked or not. If a data source is linked, changes to the dataset will carry over between the two instances. If a data source is not linked, the Data Analysis tool will create a copy of the dataset.

Sampling

To sample data from a distribution, select "Create a new dataset" and then "sampling".

Creating a sampling distribution Figure: Creating a new dataset with data sampled from a distribution.

The sampling interface Figure: A newly created sampling interface.

Click the cog icon in the sampling interface. Here, you can select one of three sampling methods:

  • Normal distribution, with parameters mu and sigma.
  • Exponential distribution, with parameter lambda.
  • Proportion distribution, with as its parameter the percentage chance of being in group 1.

The selected sampling distribution will appear at the top of the sampling home view.

The sampling settings interface Figure: The sample settings interface.

Note

Selecting a new sampling distribution or changing its parameters deletes all previously generated samples.

Click the forward button to generate a single sample, or click the +10 button to generate ten samples.

After you generate one or more samples, the latest sample will appear at the bottom of the sampling home view.

The sampling interface after generating a sample Figure: The sampling interface after generating a sample.

Uploading a dataset

The interface for uploading a CSV file Figure: The interface for uploading a CSV file.

To upload a dataset, select "Create a new dataset" and "CSV".  Use the preview to check if Algebrakit interpreted the CSV correctly.

A dataset preview of incorrectly parsed data Figure: A preview of a dataset with a semicolon delimiter with default settings.

Note

The data analysis tool does not support multiple header rows.

If the data preview looks wrong, you might need to change the column or string delimiters. Algebrakit default uses the comma between columns and the quote (") to indicate strings and text.

A dataset preview of correctly parsed data Figure: A preview of a dataset with the correct settings.

Note

Algebrakit requires CSV files to use a dot (.) as a decimal point separator. Students will see either a decimal dot (.) or a decimal comma (,) depending on their audience setting.

Creating charts

You can create a new chart by pressing the plus button in the bottom left. The chart interface allows you to create three types of charts from the data.

  • Tables, which students and authors can use to view and manipulate the data in the current dataset.
  • Charts, to represent a single variable.
  • Data plots, to visualise one variable against another.

The interface for creating a chart Figure: The interface for creating a chart.

Note

Altering values and settings in a table view updates the value or setting in the exercise's dataset.

You can export charts and plots as images.

Restrict creating diagrams

You can restrict which diagrams students can create. Checking Is Resource removes the ability for students to create new tables, charts or plots. Alternatively, you can select a subset of diagrams in the Creatable Diagrams menu. You may want a Data Analysis interaction that prevents students from creating new diagrams to support another exercise.

Note

Students can still interact with any data tables and sampling distributions that an author has created.

Manually creating a dataset

You can manually create a dataset by selecting Create new dataset as a source, and then selecting Local. Doing so takes you to an interface where you can enter your data into a data table by hand.

Uploading a student dataset

You can allow students to upload their own CSV files into the data analysis tool. To do so, select Let student upload their own CSV as the data source. This way, students can analyse data they have collected. By letting students upload their own data, you can use the Data Analysis tool to support exercises where students take measurements or perform probability experiments.