Data cleansing
Lesson details
Learning outcome
I can describe the need for data cleansing and apply data cleansing techniques to a data set.
Key learning points
- Data cleansing involves detecting and correcting, or removing, corrupt or inaccurate data.
- Data cleansing is important because real-world data is often messy, with errors or missing information.
- Once the data is clean, charts or graphs can be created to help understand patterns and trends.
Keywords
Data cleansing - the process of detecting and correcting, or removing, corrupt or inaccurate data from a data set
Common misconception
If you have missing data and cannot find the original source, there is nothing you can do.
You could look at similar data and generate an average value to insert. For example, if the zoo is missing a weight for a lion, they could calculate the average weight of the other lions and enter this.
Teacher tip
A sample data file is provided for this lesson if pupils have not collected their own data.
Equipment
Pupils will need access to a device that can access the website Codap for activities in this lesson https://oak.link/codap
Files needed for this lesson
collection-forms 14.88 MB (PDF)
litter-sample-data 20.7 KB (XLSX)
zoo-data 29.08 KB (XLSX)
Download these files to use in the lesson.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Match each step of the investigative cycle to its description:
decide what you want to find out
gather information
find patterns and trends
answer the question
Q2.What is the main purpose of a data capture form?
Q3.What word describes a question that is clear, specific, and unambiguous?
Q4.Which of these is the best example of a precise question?
Q5.Why is it important to decide what data you need before starting an investigation?
Q6.What could happen if your data capture form is unclear or confusing?
Assessment exit quiz
6 Questions
Q1.What is the process called that involves finding and fixing errors or removing incorrect information from a data set?
Q2.What is the main goal of data cleansing?
Q3.Which statement about missing data is incorrect?
Q4.Put these steps in order for preparing data for analysis:
Q5.Match each keyword to its meaning:
the process of finding and fixing errors in data
a value that is not present in the data set
showing information as a chart or graph
a typical value calculated from several numbers
Q6.Which tool can help you visualise a cleansed data set?
To help you plan your 9 computing lesson on: Data cleansing, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 9 computing lesson on: Data cleansing, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 computing lessons from the Using data science unit, dive into the full secondary computing curriculum, or learn more about lesson planning.