Evidence-Based Questions

Evidence-based questions are a fundamental component of scientific inquiry and assessment in Cambridge Primary Science. These questions require students to use information provided in texts, diagrams, data tables, graphs, or experimental results to formulate their answers, rather than relying solely on memorized facts. This approach mirrors how real scientists work—by analyzing evidence and drawing logical conclusions from observations and data.

In the Cambridge Primary curriculum, evidence-based questions develop critical thinking skills by teaching students to identify relevant information, distinguish between observations and opinions, and support their answers with specific references to source material. These questions often begin with phrases like "According to the text...", "The diagram shows...", "The data tells us...", or "What evidence supports...". They assess not just what students know, but how well they can apply their knowledge to interpret new information.

Mastering evidence-based questions is essential for success in Primary Science assessments and builds foundational skills for higher-level scientific study. Students who can effectively locate, interpret, and use evidence develop stronger reasoning abilities that extend beyond science to all academic areas. This skill also prepares students for the investigative and analytical nature of scientific work throughout their educational journey.

Evidence: Observable facts, data, measurements, or information that can be used to support or refute a statement, claim, or conclusion. In science, evidence comes from experiments, observations, texts, diagrams, or recorded data.

Evidence-based answer: A response to a question that is directly supported by specific information from a provided source, such as a passage, graph, table, diagram, or experimental result.

Source material: The text, diagram, data table, graph, photograph, or other resource provided that contains the evidence needed to answer questions.

Inference: A logical conclusion drawn from evidence and reasoning, rather than from explicit statements. Students use clues from the evidence to figure out something not directly stated.

Quote: A direct extract from written source material, usually placed in quotation marks, used as evidence to support an answer.

Data: Factual information (especially numerical) collected through observation, measurement, or experimentation that serves as evidence.

Observation: Information gathered through the senses (seeing, hearing, touching, smelling) that serves as evidence in scientific inquiry.

Support (verb): To provide evidence or reasoning that backs up a statement or conclusion; to show that a claim is valid using specific information.

Relevant evidence: Information from the source material that directly relates to and helps answer the specific question being asked.

Interpretation: The process of explaining what evidence means or represents; making sense of data, observations, or information.

Understanding the Nature of Evidence-Based Questions

Evidence-based questions in Primary Science require students to act as scientific detectives, carefully examining provided materials to extract relevant information. Unlike recall questions that test memorization, these questions assess analytical skills and the ability to work with information in context. The evidence might be presented in various formats: written passages describing experiments or observations, diagrams labeling plant or animal parts, bar graphs showing temperature changes, tables comparing properties of materials, or photographs documenting natural phenomena.

The key principle is that the answer must come from the source material, not from students' general knowledge. Even if students know correct information about a topic, they must locate and reference the specific evidence provided. For example, if a passage states "The metal spoon felt hot after sitting in boiling water," and a question asks what happened to the spoon, the correct evidence-based answer is "The spoon felt hot" or "The spoon's temperature increased," supported by that specific statement—not a general explanation about heat conduction from prior knowledge.

Types of Evidence in Primary Science

Textual evidence appears in passages describing observations, experiments, or scientific phenomena. Students must read carefully, identifying key sentences or phrases that answer questions. For instance, a passage might describe how a plant's leaves changed color over time, and students would need to locate the specific sentences describing these changes.

Visual evidence includes diagrams, photographs, and illustrations. These might show the parts of a flower, stages of a life cycle, or comparative sizes of objects. Students must interpret what they see and relate it to questions asked. A diagram showing arrows indicating water movement through a plant provides visual evidence of transpiration.

Numerical evidence comes from data tables, measurements, and graphs. Students extract specific values (temperatures, lengths, times) and identify patterns or trends. A bar graph showing plant growth over four weeks provides evidence about which conditions produced the tallest plant.

Comparative evidence allows students to identify differences or similarities between conditions, groups, or time periods. Tables comparing how different materials react to water (floating vs. sinking) provide comparative evidence about material properties.

Locating Relevant Evidence

The skill of finding pertinent information quickly and accurately is crucial. Students should follow these steps:

1. Read the question carefully to identify exactly what information is needed
2. Identify key words in the question that signal what to look for in the source material
3. Scan the source for those key words or related terms
4. Read around the key words to understand the context and extract complete information
5. Verify relevance by checking that the information truly answers the question asked

For example, if asked "What evidence shows that exercise affects heart rate?", students should look for words like "exercise," "heart rate," "beats per minute," "physical activity," or related terms in the source material, then read those sections thoroughly.

Supporting Answers with Evidence

Once evidence is located, students must explicitly connect it to their answer. This involves:

• Quoting directly from text sources when appropriate: "The text states that 'the ice melted completely after 15 minutes'"
• Referencing specific data points: "According to the table, Plant A grew 12 cm while Plant B grew only 8 cm"
• Describing visual evidence: "The diagram shows that warm air rises while cool air sinks, indicated by the arrows"
• Using appropriate scientific vocabulary from the source material to demonstrate understanding

Weak answers simply state conclusions without showing where they came from. Strong answers explicitly link back to the source: "I know this because..." or "The evidence for this is..." or "This is shown by..."

Making Valid Inferences from Evidence

Some evidence-based questions require inference—using evidence to figure out something not directly stated. Students combine provided evidence with scientific understanding to reach logical conclusions. For instance, if data shows a plant receiving sunlight grew taller than one kept in darkness, students can infer that sunlight is necessary for plant growth, even if the text doesn't explicitly state this conclusion.

Valid inferences must be:

• Logically connected to the evidence
• Consistent with all provided information
• Based on multiple pieces of evidence when available
• Scientific rather than imaginative or speculative

Worked Example 1: Using Textual Evidence

Source Passage: "During our experiment with magnets, we tested different materials. The iron nail and steel paper clip both stuck firmly to the magnet. The plastic button, wooden stick, and aluminum foil did not attach to the magnet at all. We observed that the copper coin slid off the magnet immediately when we tried to pick it up."

Question: What evidence shows that plastic is not a magnetic material?

Worked Solution:

Step 1 - Identify what the question asks: The question asks specifically about evidence that plastic is not magnetic.

Step 2 - Locate relevant information: Scan the passage for mentions of "plastic." Found: "The plastic button...did not attach to the magnet at all."

Step 3 - Formulate evidence-based answer: "The evidence that plastic is not magnetic is that the plastic button did not attach to the magnet at all."

Step 4 - Check completeness: The answer quotes/paraphrases the source, specifically mentions plastic, and explains what happened (did not attach), showing it is not magnetic.

Full answer: The passage states that "the plastic button...did not attach to the magnet at all," which shows that plastic is not a magnetic material.

Why this is strong: It quotes the source directly, identifies the specific material (plastic button), and explains what the evidence demonstrates about plastic's properties.

Worked Example 2: Using Data from a Table

Source Material: Table showing water temperature changes:

Question: What does the data tell us about how water temperature changed over time?

Worked Solution:

Step 1 - Examine the table structure: Note that time increases from 0-20 minutes, and there is a corresponding temperature measurement for each time point.

Step 2 - Identify the pattern: Temperature values decrease as time increases (100→85→72→61→54).

Step 3 - Quantify the change: Calculate the total change: 100°C - 54°C = 46°C decrease over 20 minutes.

Step 4 - Reference specific data points: Use actual numbers from the table to support observations.

Full answer: The data shows that the water temperature decreased over time. At the start (0 minutes), the water was 100°C, but by 20 minutes it had cooled to 54°C. This is a decrease of 46°C. The temperature dropped steadily at each 5-minute interval, showing that the water lost heat continuously throughout the experiment.

Why this is strong: It identifies the trend (decreasing), provides specific data points from the table (100°C, 54°C), calculates the total change (46°C), and describes the pattern across all intervals.

Worked Example 3: Using a Diagram

Source Material: [Diagram description: A labeled diagram of a plant showing roots underground, a stem above ground, leaves on branches, and a flower at the top. Arrows show water moving up from roots through the stem to leaves.]

Question: According to the diagram, how does water travel through the plant?

Worked Solution:

Step 1 - Examine the diagram carefully: Look at all labels, arrows, and the positions of plant parts.

Step 2 - Focus on water-related features: Notice the arrows showing direction of water movement.

Step 3 - Trace the path: Follow the arrows from their starting point to ending point.

Step 4 - Use correct terminology: Identify plant parts by their labeled names (roots, stem, leaves).

Full answer: The diagram shows that water travels upward through the plant. The arrows indicate that water starts in the roots, which are underground. It then moves up through the stem and finally reaches the leaves. The arrows point in one direction—from roots→stem→leaves—showing the path water takes as it moves through the plant.

Why this is strong: It describes what the diagram shows (arrows), identifies the direction (upward), names specific plant parts in sequence (roots, stem, leaves), and explains what the visual evidence demonstrates about water movement.

Question Type 1: Direct Evidence Extraction

Example Question: "Read the following passage: 'We placed four bean seeds in different conditions. Seed A received water and sunlight daily. Seed B received only water. Seed C received only sunlight. Seed D received neither water nor sunlight. After two weeks, only Seed A had sprouted and grown into a small plant.'

According to the experiment, which seed grew into a plant?"

How to Answer:

• Step 1: Identify the specific question focus—which seed grew
• Step 2: Scan the passage for keywords: "grew," "plant," "sprouted"
• Step 3: Locate the relevant sentence: "After two weeks, only Seed A had sprouted and grown into a small plant"
• Step 4: Extract the direct answer: Seed A
• Step 5: Support with evidence from the text

Model Answer: Seed A grew into a plant. The passage states that "only Seed A had sprouted and grown into a small plant" after two weeks, showing it was the only seed that successfully developed.

Mark Scheme Focus: Full marks require identifying the correct seed (Seed A) AND providing evidence from the passage to support the answer.

Question Type 2: Comparing Evidence

Example Question: "The table below shows how far three different toy cars traveled on different surfaces:

What does this data tell us about how surface type affects how far the cars travel?"

How to Answer:

• Step 1: Examine all data points systematically
• Step 2: Identify the relationship or pattern between variables
• Step 3: Compare specific values to support observations
• Step 4: Make clear statements about what the evidence shows

Model Answer: The data shows that surface type significantly affects how far the toy cars travel. On the smooth tile surface, the car traveled the farthest distance of 45 cm. On carpet, the distance was much shorter at 15 cm, and on rough sandpaper, the car traveled the shortest distance of only 8 cm. This evidence suggests that smoother surfaces allow cars to travel farther, while rougher surfaces reduce the distance traveled.

Mark Scheme Focus: Must reference specific data values, compare at least two surfaces, and explain the relationship between surface type and distance traveled.

Question Type 3: Drawing Inferences from Evidence

Example Question: "During an investigation, students measured the shadow length of a stick at different times:

• 9:00 AM: shadow length = 80 cm
• 12:00 PM: shadow length = 20 cm
• 3:00 PM: shadow length = 75 cm

What can you infer about the Sun's position based on this evidence?"

How to Answer:

• Step 1: Analyze the pattern in the data (shadow lengths change over time)
• Step 2: Connect to scientific knowledge (Sun's position affects shadow length)
• Step 3: Make logical inference based on the evidence
• Step 4: Explain the reasoning linking evidence to inference

Model Answer: From this evidence, I can infer that the Sun's position in the sky changed throughout the day. At 12:00 PM (midday), the shadow was shortest at 20 cm, which suggests the Sun was highest in the sky at that time. At 9:00 AM and 3:00 PM, the shadows were much longer (80 cm and 75 cm), suggesting the Sun was lower in the sky during morning and afternoon. This pattern shows that the Sun moves across the sky during the day, being highest at midday.

Mark Scheme Focus: Must use specific data, make a valid inference about Sun position, and explain the logical connection between shadow length and Sun position.

Question Type 4: Evaluating Evidence Quality

Example Question: "A student concluded that 'plants don't need water to grow' after observing one plant survive for three