Complete the Investigation

Overview

In this penultimate unit lesson, learners complete a full statistical investigation using a non-sensitive question about the class. They apply prior learning about data displays and variability to collect, represent and interpret data, then communicate a conclusion supported by evidence.

Learning intentions

• WALT pose a clear statistical question and choose fair, non-overlapping categories.
• WALT collect and organise data accurately in a table and graph.
• WALT describe what the data shows, including variation between categories.
• WALT communicate a conclusion using evidence and suggest a follow-up question.

Success criteria

• I can write a question that can be answered by surveying our class.
• I can make categories that are fair and count every response once.
• I can check that my table total matches the number surveyed and create an accurate graph.
• I can use data from my table or graph to explain a conclusion.

Curriculum links

• Mathematics and Statistics — Mathsteasers: applying higher-order thinking to a meaningful mathematical investigation.
• Mathsteasers / Alignment: connecting statistical investigation processes with familiar classroom mathematics.
• Mathsteasers — Additional resources for advanced learners: extending learners through choice, reasoning, interpretation and follow-up questions.
• The key competencies are practised through managing self, participating and contributing, communicating, and thinking.

Lesson structure (60 minutes)

1. 0–7 min · Hook and success check. Teacher opens the investigation introduction slides and displays two deliberately flawed graphs: one with a missing title and one whose totals do not match the survey size. Students identify what a trustworthy investigation must include and revisit the Must Do, Can Do and Try goals.

2. 7–15 min · Model the investigation cycle. Teacher models turning a broad idea such as “What do we like?” into a fair question, for example, “Which type of book would you most like to read next?” with clear, non-overlapping categories. Students suggest suitable non-sensitive topics, test whether each question can be answered by everyone, and predict which category may be most common.

3. 15–23 min · Plan and organise teams. Teacher places learners in flexible teams of three or four and distributes the statistical investigation booklet. Explain roles such as question reader, recorder, checker and graph maker; roles may be shared. Students complete the question, prediction, categories and collection method, checking that categories are fair and that every response will be counted once.

4. 23–35 min · Collect and record data. Teacher supervises teams as they survey classmates, reminding them to ask the same question in the same way and to use tally marks carefully. Students collect one response from each class member, then transfer tallies and frequencies into a table in the booklet; early finishers use the category totals to check their calculations.

5. 35–50 min · Create and interpret a graph. Teacher provides the bar graph template pack where helpful and prompts teams to include a meaningful title, category labels, a labelled vertical scale, equal intervals and bars that match the table. Students create a bar graph, check that the frequencies add to 25, and write two observations describing the most common, least common or differing categories.

6. 50–60 min · Communicate and reflect. Teacher invites each team to give a brief gallery presentation, display a poster, show a model or digital graph, or record an oral explanation in a quiet space; use the discussion and reflection slides for feedback prompts. Students communicate a supported conclusion using evidence, respond to one question, and complete the Try challenge by proposing a sensible follow-up investigation.

Resources

• the investigation introduction slides
• the statistical investigation booklet
• the bar graph template pack
• Pencils, coloured pencils, rulers and erasers
• Large paper or poster paper
• Clipboards or firm writing surfaces
• Optional tablets or computers with a simple graphing tool
• Quiet recording space and headphones, if available
• Timer and team role cards

Assessment

• During planning, check that each question is answerable, categories are fair and every response has a place.
• During table and graph construction, check that totals equal 25, tally marks are grouped correctly, titles and labels are present, and the scale is consistent.
• Use the presentation and booklet to assess whether conclusions refer to specific evidence. Ask learners to explain how the graph supports their claim.

Differentiation

• Provide question examples, category prompts and sentence starters such as “The most common response was ___, with ___ people” and “This shows that ___”.
• Pair learners strategically and assign roles that support participation; allow drawing, pointing, oral explanation, audio recording or digital presentation instead of extended writing.
• Offer a pre-selected question and categories, a partially completed table, or a graph with the scale started for learners needing additional support.
• Extend confident learners by asking them to describe variability between categories, justify their scale, compare two representations, or explain a limitation and refine the follow-up question.
• For EAL learners, use pictures or gestures for survey categories, rehearse the question orally, and provide key words including question, category, tally, frequency, graph, evidence and conclusion.