Sample work Science 7–10 Stage 4: Investigating Plants

Description of activity

Students plan and perform a controlled investigation to test a question or hypothesis. They record their measurements and communicate their method, results and conclusion in a report. An information sheet is given to students which provides some examples of questions that could be investigated and instructions for planning their experiment.

Information Sheet

Examples of questions that could be investigated.

• Is plant growth related to the amount of fertiliser used?
• Will plants watered with soapy water grow as tall as plants watered with plain water?
• Will plants watered with salty water grow as tall as plants watered with plain water?
• Do different coloured lights affect the growth rate of plants?
• Is plant growth related to how deep under the soil surface seeds are sown?
• Can salty water affect seed germination?
• Can soapy water affect seed germination?
• Do microwaves affect seed germination?
• Does temperature affect the time it takes seeds to germinate?

Planning the Investigation

1. Write a hypothesis which states what you think the solution to your selected problem will be.
2. Design a fair test for your hypothesis.
   Remember you must:
   • change something (independent variable)
   • measure something (dependent variable)
   • keep everything else the same (controlled variables)
   • repeat your trials and average your results.

3. Put a control in your investigation.
4. Develop a plan.
5. Set up and carry out the investigation and record the results in a table.
6. Write your report. 
   Include: title, hypothesis, equipment list, method, diagram, results (in a table), graph, discussion and conclusion.

Context

Students have an understanding of plant growth requirements and the role of the root, stem and leaf in flowering plants. They have developed skills in planning and performing first-hand investigations to test ideas. Students have written reports that clearly record data and information and include a discussion of their findings.

Outcomes

A student:

4.10 identifies factors affecting survival of organisms in an ecosystem
4.13 clarifies the purpose of an investigation and, with guidance, produces a plan to investigate a problem
4.17 evaluates the relevance of data and information
4.18 with guidance, presents information to an audience to achieve a particular purpose
4.19 draws conclusions based on information available

Criteria for assessing learning

(These criteria would normally be communicated to students with the activity.)

Students will be assessed on their ability to:

• write a hypothesis to be tested in a first-hand investigation
• design an investigation to test the hypothesis that is fair and includes a control
• record gathered data and information using tables, graphs and diagrams
• write a report which includes a method, results and conclusion as record of the investigation
• discuss results and problems that arise in the investigation.

Work Sample Assessment

Huong

Huong has produced a report that demonstrates thorough knowledge and understanding of experimental design. A high level of competence in planning, conducting and reporting a controlled investigation is evident. Huong has identified variables that need to be controlled in the investigation and there is some evidence of both replication and repetition in the method described. The different aspects of the report have been thoroughly addressed but the labelling of the table and graph could be clearer. Underlying scientific principles have been identified and the suggestions for improving the experimental design imply high-level evaluation skills. Huong has attempted to relate the conclusion to the aim, but the results do not fully support this. This work sample demonstrates characteristics of work typically produced by a student performing at grade B standard.

Nicky

Nicky has produced a report that demonstrates thorough knowledge and understanding of experimental design. A high level of competence in planning, conducting and reporting a controlled investigation is evident. Nicky has provided evidence of controlling variables in the method and has attempted to increase the reliability of the data collected. There is no evidence of the use of a control in the investigation. Nicky has demonstrated a high level of competence in tabulation and graphing skills. A valid conclusion has been drawn and there is some evidence of critical thinking. This work sample demonstrates characteristics of work typically produced by a student performing at grade B standard.

Jules

Jules has produced a report that demonstrates sound knowledge and understanding of experimental deign. A testable hypothesis and a method that includes some elements of sound experimental design have been presented. Jules has planned an investigation which includes one independent variable (presence of food dye) and an attempt to control other variables (seed numbers, value of water). There is evidence of an adequate level of competence in systematically gathering data from qualitative and quantitative observations and in recording results in a table. The graph includes a key, but some data has not been accurately presented. While the discussion shows some analytical skill and recognises areas for improvement, Jules has produced a conclusion that does not reflect the hypothesis and findings of the investigation. This work sample demonstrates characteristics of work typically produced by a student performing at grade C standard.

Shane

Shane has produced a report that demonstrates sound knowledge and understanding of experimental design. An adequate level of competence in planning, conducting and reporting a controlled investigation is evident. Shane has related the hypothesis to the aim of the investigation and clearly identified the variables. The method lacks some detail and there is little evidence of attempting to increase the reliability of the data gathered. A graph has been included, and the results have been recorded in a table but not in the most efficient manner. While the conclusion does not fully address the aim, Shane has provided some evidence of critical thinking by offering a plausible explanation of the results obtained. This work sample demonstrates characteristics of work typically produced by a student performing at grade C standard.

Ali

Ali has produced a report that demonstrates a basic knowledge and understanding of the elements of experimental design. A simplistic plan that attempts to test the hypothesis has been developed. The method lacks detail and does not clearly show how the investigation would produce valid or reliable results. Ali has presented the data in a table, and a basic graph has been used. The discussion summarises the results but does not identify improvements in the design of the investigation. This work sample demonstrates characteristics of work typically produced by a student performing at grade D standard.

Bailey

Bailey has produced a report that demonstrates basic knowledge and understanding of experimental design. A limited level of competence in planning, conducting and reporting a controlled investigation is evident. The method is a simplistic plan that does not address the hypothesis indicated and shows little understanding of the features of a controlled investigation. Bailey has demonstrated a limited level of competence in graphing data, and the discussion is unclear. This work sample demonstrates characteristics of work typically produced by a student performing at grade D standard.

Ariel

Ariel has produced a report that demonstrates basic knowledge and understanding of experimental design. A limited level of competence in planning, conducting and reporting a controlled investigation is evident. Ariel has provided a simplistic plan with limited evidence of identifying and controlling variables. The report lacks a hypothesis and the use of a control. The results have not been graphed. The conclusion does not relate to the aim and there is no evidence of a discussion. This work sample demonstrates characteristics of work typically produced by a student performing at grade D standard.

Shannon

Shannon has produced a report that demonstrates elementary knowledge and understanding of experimental design. A very limited level of competence in planning, conducting and reporting a controlled investigation is evident. The experimental report is of an elementary standard as it lacks a hypothesis and the graph shows a very limited level of competence in recording data. The aim of the investigation is unclear and Shannon has not identified the variables that need to be controlled to make the investigation a fair test. There is no evidence of the use of a control in the investigation. An attempt to provide a conclusion has been made but it has not been based on the data collected. This work sample demonstrates characteristics of work typically produced by a student performing at grade E standard.