Scientific Investigation

The scientific method is a systematic method in doing their work.

A report of the investigation must include:

  1. Objective of the experiment,
  2. Inference,
  3. Hypothesis,
  4. Three types of variables: manipulated variable, responding variable and fixed variable,
  5. Defined operational variables,
  6. List of apparatus,
  7. Procedure,
  8. Tabulation of data,
  9. Analysis of data,
  10. Conclusion.

Inference is a statement to state the relationship between two visible quantities observed in a diagram or picture.
Hypothesis is a statement to state the relationship between two measurable variables that can be investigated in a lab.
The Variables
A variable is a quantity that can vary in value. There are 3 types of variable:

  1. Manipulated Variables: Manipulated variables are factors which changed for the experiment.
  2. Responding Variables: Responding variables are factors which depend on the manipulated variables.
  3. Constant Variables: Constant variables are factors which are kept the same throughout the experiment.

Tabulating Data
A proper way of tabulating data should include the following:

  1. The name or the symbols of the variables must be labelled with respective units.
  2. All measurements must be consistent with the sensitivity of the instruments used.
  3. All the values must be consistent to the same number of decimal places.

The Graph
Graphs are used to make a relationship between variables.
Gradient value and extrapolation of a graph are used to analyse a graph.
A well-plotted must contain the following features:

  1. A title to show the two variables under investigation,
  2. two axes labelled with the correct variables and their respective units,
  3. the graph drawn is greater than 50 % of the graph paper,
  4. appropriate scales (1:1 x 10x, 1:2 x 10x and 1:5 x 10x)
  5. all the points are correctly plotted,
  6. a best fit line is drawn