Presenting Data – Graphs and TablesTypes that Data

There space different species of data that can be collected in one experiment. Typically, we try to design experiments that collect objective, quantitative data.

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Objective data is fact-based, measurable, and observable. This method that if two world made the same measurement v the exact same tool, lock would acquire the exact same answer. The measure is determined by the object that is gift measured. The size of a worm measured v a ruler is an target measurement. The observation that a chemical reaction in a check tube readjusted color is an target measurement. Both that these are observable facts.

Subjective data is based on opinions, clues of view, or emotionally judgment. Spatu data might give two various answers when collected by two different people. The measure up is determined by the topic who is law the measuring. Surveying people around which of 2 chemicals smells worse is a subjective measurement. Grading the high quality of a presentation is a spatu measurement. Rating her relative joy on a scale of 1-5 is a spatu measurement. Every one of these count on the human being who is making the observation – someone else can make these dimensions differently.

Quantitative measurements gather numerical data. Because that example, measure a worm together being 5cm in length is a quantitative measurement.

Qualitative measurements explain a quality, rather than a numerical value. Saying the one worm is much longer than one more worm is a qualitative measurement.

ObjectiveThe chemistry reaction has developed 5cm of bubbles.The chemical reaction has produced a lot of bubbles.
SubjectiveI provide the quantity of bubbles a score that 7 top top a range of 1-10.I think the bubbles space pretty.

After girlfriend have collected data in one experiment, you require to figure out the best way to present that data in a systematic way. Depending on the form of data, and also the story that you room trying to tell making use of that data, you may current your data in different ways.


You are evaluating the result of different varieties of fertilizer on tree growth. You tree 12 tomato plants and divide them into three groups, whereby each group contains four plants. To the first group, you perform not include fertilizer and the plants space watered with level water. The 2nd and third groups are watered through two different brands the fertilizer. After 3 weeks, you measure the growth of each plant in centimeters and also calculate the average growth for each form of fertilizer.

The result of different brands the fertilizer on tomato plant expansion over three weeks
TreatmentPlant Number
No treatment1012899.75
Brand A1516141214.25
Brand B2225212723.75

Scientific technique Review: Can you identify the an essential parts that the scientific an approach from this experiment?

Independent variable – type of therapy (brand that fertilizer)Dependent variable – plant expansion in cmControl group(s) – plants treated through no fertilizerExperimental group(s) – plants treated with different brands the fertilizer
Graphing data

Graphs are used to display screen data because it is easier to see patterns in the data once it is displayed visually compared to as soon as it is displayed numerically in a table. Complex data can often be displayed and interpreted more easily in a graph style than in a data table.

In a graph, the X-axis runs horizontally (side come side) and also the Y-axis runs vertically (up and also down). Typically, the live independence variable will certainly be displayed on the X axis and also the dependence variable will certainly be displayed on the Y axis (just choose you learned in mathematics class!).

Line Graph

Line graphs room the best type of graph come use as soon as you space displaying a readjust in something over a consistent range. For example, you might use a heat graph to display screen a change in temperature over time. Time is a constant variable because it deserve to have any type of value in between two offered measurements. That is measured follow me a continuum. Between 1 minute and also 2 minutes room an infinite number of values, such together 1.1 minute or 1.93456 minutes.

Changes in several different samples deserve to be shown on the same graph by using lines that differ in color, symbol, etc.

Figure 1: change in bubble elevation in centimeters end 120 secs for 3 samples comprise different quantities of enzyme. Sample A contained no enzyme, sample B had 1mL the enzyme, sample C included 2 mL of enzyme.

Bar Graph

Bar graphs are used to to compare measurements in between different groups. Bar graphs should be used when her data is no continuous, yet rather is split into various categories. If you counted the number of birds of various species, each varieties of bird would be its own category. Over there is no value between “robin” and also “eagle”, so this data is no continuous.

Figure 2: Final bubble height after 120 secs for 3 samples containing different combinations of ingredients. Sample A included enzyme however no substrate, sample B included substrate yet no enzyme, sample C had substrate and enzyme.

Scatter Plot

Scatter Plots are provided to evaluate the relationship between two different consistent variables. These graphs compare transforms in two different variables in ~ once. For example, you can look in ~ the relationship between height and weight. Both height and also weight are continuous variables. You could not use a scatter plot to look at the partnership between variety of children in a family and also weight of each child since the variety of children in a family is not a consistent variable: you can’t have 2.3 children in a family.

Figure 3: The relationship between height (in meters) and also weight (in kilograms) of members that the girls soft ball team. “OLS instance weight vs height scatterplot” by Stpasha is in the Public Domain


Let’s go back to the data from ours fertilizer experiment and also use it to do a graph. I’ve determined to graph only the average expansion for the four plants due to the fact that that is the most necessary piece that data. Consisting of every solitary data suggest would make the graph very confusing.

The independent variable is kind of treatment and the dependent change is plant growth (in cm).Type of therapy is not a constant variable. There is no midpoint value in between fertilizer brand (Brand A 1/2 doesn’t make sense). Plant growth is a constant variable. It makes sense to sub-divide centimeters into smaller values. Since the independent change is categorical and also the dependent change is continuous, this graph should be a bar graph.Plant expansion (the dependence variable) need to go top top the Y axis and kind of treatment (the elevation variable) must go on the X axis.Notice the the worths on the Y axis are constant and evenly spaced. Each line represents an increase of 5cm.Notice that both the X and also the Y axis have labels that incorporate units (when required).Notice the the graph has a descriptive inscription that permits the figure to was standing alone without additional information given from the procedure: you recognize that this graph mirrors the median of the measurements taken from 4 tomato plants.

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Figure 4: Average growth (in cm) of tomato plants once treated with different brands the fertilizer. There were 4 tomato plants in each team (n = 4).
Descriptive captions

All figures that present data should stand alone – this method that friend should have the ability to interpret the information included in the number without introduce to anything rather (such together the methods section the the paper). This way that all figures should have actually a descriptive inscription that offers information around the independent and dependent variable. Another means to state this is the the caption should describe what you room testing and also what you room measuring. A great starting suggest to occurring a subtitle is “the result of on the .”

Here room some instances of good caption for figures:

The effect of exercise on love rateGrowth rates of E. Coli at different temperaturesThe relationship between heat shock time and transformation efficiency

Here room a few less effective captions:

Heart rate and exerciseGraph the E. Coli temperature growthTable for experiment 1