Graph and Table drawing

Starter - What’s wrong? Pulse rate (beats/m) walking Exercise started Running started Time (min) Oxygen released Time (min) pulse ratetime

Which Graph? When should you use each graph? Line – Bar - Scattergram - A. IV is discontinuous and DV continuously variable B. between two continuous variables, a causal link cannot be assumed (usually as it is one variable out of many) C. Between two continuous variables, a likely causal link between the IV and DV.

Presenting your graph Join with a curve if the trend is very clear and you can predict the values in between the points Join with straight lines when the trend is not clear and the values in between the points cannot be assumed/predicted Bar charts – bars must be separated from each other. If the bars touch it is a histogram!

InvestigationIndependent variable and type Dependent Variable and type Type of graph Effect of Temp on release of oxygen from hydrogen peroxide by catalase Frequency of blood group A in age groups and Effect of soil pH on percentage of variegated clover leaves Effect of water potential of surrounding solution on water gain/loss of potato tissue Effect of intensity of exercise on heart rate

Complete the table below InvestigationIndependent variable and type Dependent Variable and type Type of graph Effect of Temp on release of oxygen from hydrogen peroxide by catalase Frequency of blood group A in age groups and Effect of soil pH on percentage of variegated clover leaves Effect of water potential of surrounding solution on water gain/loss of potato tissue Effect of intensity of exercise on heart rate

Complete the table below InvestigationIndependent variable and type Dependent Variable and type Type of graph Effect of Temp on release of oxygen from hydrogen peroxide by catalase Temperature (continuous) Volume of oxygen (continuous) Line Frequency of blood group A in age groups and Ages (discontinuous) Frequency (continuous) Bar Effect of soil pH on percentage of variegated clover leaves pH (continuous) percentage of clover (continuous) Scattergram (can’t control other variables in the field) Effect of water potential of surrounding solution on water gain/loss of potato tissue Water potential (continuous) Change in mass (continuous) Line (may need + and – values) Effect of intensity of exercise on heart rate Intensity of exercise (continuous) Heart rate (continuous) line

Other key words Mean Median Mode Range B. The average of the numbers: a calculated "central" value of a set of numbers. To calculate: Just add up all the numbers, then divide by how many numbers there are C. The middle number (in a sorted list of numbers). To calculate: place the numbers you are given in value order and find the middle number. D. The number which appears most often in a set of numbers. A. The difference between the lowest and highest values. To calculate: e.g. In {4, 6, 9, 3, 7} the lowest value is 3, and the highest is 9, so it is 9 − 3 = 6.

Table rules

Tables The following guidelines should be followed when presenting results in tables. All raw data in a single table with ruled lines and border. Independent variable (IV) in the first column; dependent variable (DV) in columns to the right (for quantitative observations) OR descriptive comments in columns to the right (for qualitative observations). Processed data (e.g. means, rates, standard deviations) in columns to the far right. No calculations in the table, only calculated values.

Tables Each column headed with informative description (for qualitative data) or physical quantity and correct SI units (for quantitative data); units separated from physical quantity using either brackets or a solidus (slash). No units in the body of the table, only in the column headings. Raw data recorded to a number of decimal places and significant figures appropriate to the least accurate piece of equipment used to measure it. All raw data recorded to the same number of decimal places and significant figures. Processed data recorded to up to one decimal place more than the raw data.

Graph rules The following general guidelines should be followed when presenting data in graphs: The type of graph used (e.g. bar chart, histogram, line graph, pie chart or scattergram) should be appropriate to the data collected. The graph should be of an appropriate size to make good use of the paper. There should be an informative title, and axes should be fully labelled with units.

Bar charts and histograms These are used when the dependent variable on the y-axis is discrete, i.e. whole numbers, fractions are impossible and the data under consideration deal with frequencies. Bar charts are used when the independent variable is non-numerical, e.g. the number of different insect species found on trees. These data are discontinuous. They can be made up of lines, or blocks of equal width, which do not touch. The lines or blocks can be arranged in any order, but it can aid comparison if they are arranged in descending order of size. Histograms can be used if the data is discrete but continuous

The data from table 3.1 can be organised into classes. Fill in the table below. Data Handling - Worksheet Plot the most suitable graph of the data above.

Draw your graph Use your data to draw a graph. Are the data continuous or non- continuous? What sort of graph should you draw?

Peer Assess table and graph STAR time – make improvements in purple.

Answers Graph should be a histogram (bars touch as x axis is continuous) Should be a key as two sets of data X axis height (mm) Y axis number of dog whelks per class (or /class) Good use of paper and equidistant axes