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Obtaining, analysing and evaluating results – WJECConcluding – looking for patterns

Under the new GCSE specifications in Wales, practical work in Science will be examined. This unit will help students to prepare for the practical examination.

Part of Biology (Single Science)Practical skills

Concluding – looking for patterns

Looking for patterns, trends and correlations in graphs

In this part of the paper, you will have to analyse your data and suggest or confirm a relationship between the independent variable (A), and the dependent variable (B). Here are some examples of relationships from graphs.

No correlation between variables A and B.

Variable A changes, B doesn’t change.

Variable B is independent of variable A.

A graph with the x axis labelled A and the y axis labelled B. A line runs horizontally from the y axis.

Direct proportion between A and B.

A changes, B changes in the same ratio, eg if A doubles, so does B.

A graph that shows direct proportion is a straight rising line that goes through the origin.

An example of this might be if A is the resultant force on a dynamics trolley and B is the acceleration of the trolley. The acceleration of the trolley is directly proportional to the resultant force.

A graph with the x axis labelled A and the y axis labelled B. A line runs upwards diagonally from the origin.

A and B are proportional to each other.

Variable A changes by a regular amount and so does B.

The graph does not go through the origin.

An example of this might be if A is a weight added to a spring and B is the length of the spring. The length of the spring is proportional to the weight added to it.

A graph with the x axis labelled A and the y axis labelled B. A line runs upwards diagonally from a point on the y axis.

There is an increasing positive correlation between variables A and B.

A increases by a regular amount.

B increases at an increasing rate.

A graph with the x axis labelled A and the y axis labelled B. A curved line runs horizontally from the origin and rises upwards.

There is a decreasing positive correlation between variables A and B.

A increases by a regular amount.

B increases at a decreasing rate.

A graph with the x axis labelled A and the y axis labelled B. A curved line runs vertically from the origin and then flattens.

Variables A and B show negative correlation to each other.

A increases by a regular amount.

B decreases by a regular amount.

A graph with the x axis labelled A and the y axis labelled B. A line runs downwards diagonally from the y axis to the x axis.

Variables A and B are inversely proportional to each other.

As A increases, B decreases.

As A doubles, B halves.

An example of this might be if A was the mass of a dynamics trolley and B was its acceleration. The acceleration of the trolley is inversely proportional to the mass of the trolley.

A graph with the x axis labelled A and the y axis labelled B. A concave curved line runs vertically from B to A.