Lessons 1–2 · 2 lessons · K. T. Suyarov, Z. B. Sangirova, M. T. Umaraliyeva, S. G‘. Xasanova, M. K. Yuldasheva, D. T. Hasanova. Natural Science, Grade 6 (new edition). Republican Education Centre, 2022
2
Planning a scientific investigation
Textbook, pp. 8–10
GoalList the steps of a research plan and the methods of studying nature, and explain why a control group is needed.
New words
research aim (the result you want at the end) · tadqiqot maqsadiexperiment (you act on the object to see what happens) · tajriba (eksperiment)control group (kept in normal conditions for comparison) · nazorat guruhimodelling (studying an object through its model) · modellashtirish
Explanation
A research plan has six steps: 1) choose the topic; 2) set the aim and tasks; 3) fix the object and subject; 4) choose the methods; 5) collect data, observe and experiment; 6) evaluate the results and draw a conclusion. The aim is the result you want at the end; the tasks are the ways to reach it. There are five methods of studying nature: observation and description, measuring, experiment, comparison and modelling. In observation the researcher does not interfere; in an experiment the researcher acts on the object. For a reliable conclusion an experiment uses an experimental group and a control group: the control group stays in normal conditions and is used for comparison.
Worked examples
How does watering affect plant growth? Three plants of the same kind are taken: the first gets a lot of water, the second a little (experimental group), the third the usual amount (control group). Height and the number of leaves are recorded in a diary.
Name the method: measuring a leaf with a ruler – measuring; studying Earth’s shape on a globe – modelling; comparing two leaves – comparison; writing down birds’ behaviour without disturbing them – observation.
Class activity
“Young researchers” experiment: put damp cotton wool in three cups and the same number of cress (or bean) seeds in each. Moisten the first a lot, the second a little and the third normally every day. For 7–10 days measure the shoots with a ruler and record them in a diary. Safety: do not eat the seeds, wash hands after the work, and if mould appears, do not touch it and tell an adult.
Practice
1
List the six steps of a research plan in order.
Choose the topic; aim and tasks; object and subject; methods; collect data, observe, experiment; evaluate results and conclude.
2
What is the main difference between observation and experiment?
In observation we do not affect the object; in an experiment the researcher acts on the object.
3
Which instrument measures temperature and which measures mass?
Temperature – thermometer; mass – balance (scales).
4
Why is a control group needed in an experiment?
To compare the results with normal conditions and show that the change really comes from the factor being tested.