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# Science Exam Tips and Strategies: GED Test Prep (page 2)

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Updated on Mar 23, 2011

Up to 60% of all GED Science Exam questions include graphics. By becoming familiar with different types of graphics and learning about their essential components, you will be better prepared to answer GED Science Exam questions that contain graphical information.

When looking at a chart or a graph, look at the title or caption first. This will give you an overview of what the graphic is showing. Next, look at any legends or axis labels provided. This will give you an idea of what variables are shown. Make a list of the variables. Once you have done that, you can try to interpret the chart or graph by noting any trends you may see. How is one variable changing in response to the other? Next, you can read the question and attempt to answer it. Here is more specific information about graphics.

### Charts

All charts are composed of rows (horizontal) and columns (vertical). Entries in a single row of a chart usually have something in common, and so do entries in a single column. Determine what the common elements are when you try to answer the questions on the GED Science Exam.

### Graphs

Three common types of graphs are scatter plots, bar graphs, and pie graphs. Here you will find a brief description of each.

Whenever a variable depends continuously on another variable, this dependence can be visually represented in a scatter plot. Examples include a change in a property (such as human population) as a function of time. A scatter plot consists of the horizontal (x) axis, the vertical (y) axis, and collected data points for variable y, measured at variable x. The variable points are often connected with a line or a curve. A graph often contains a legend, especially if there is more than one data set or more than one variable. A legend is a key for interpreting the graph.

Look at the sample graph. The essential elements of the graph—the x- and y-axes—are labeled. The legend to the right of the graph shows that dots are used to represent the variable points in data set 1, while squares are used to represent the variable points in data set 2. If only one data set exists, the use of a legend is not essential.

Bar graphs are similar to scatter plots. Both have a variable y plotted against a variable x. However, in bar graphs data is represented by bars, rather than by points connected with a line. Bar graphs are often used to indicate an amount or level, as opposed to a continuous change. Pie graphs are often used to show what percentage of a total is taken up by different components of that whole.

### Diagrams

Diagrams could be used to show a sequence of events, a chemical or biological process, the setup of a science experiment, a phenomenon, the relationship between different events or beings, and so forth. When you see a diagram, first ask yourself what its purpose is. What is it trying to illustrate? Then look at the different labeled parts of the diagram. What is their function? How are they interrelated?

### Reading and Understanding Scientific Passages

When you read a scientific passage, the most important thing is to focus on the big picture, or on what the passage is about. In many ways, the reading passages in the science part of the GED are the same as the reading passages in other areas. One important difference is that science passages may expose you to science jargon, specialized vocabulary you may not be familiar with. Try not to let new words throw you off. You may be able to guess their meaning from the context. Even if you can't, keep reading. The questions following the passage may not require you to understand that particular word.

### Series of Questions Based on a Passage or Graphic

On the GED Science Exam, you will sometimes be asked more than one question based on the same graphic or passage. When this is the case, it is worth your while to invest a little more time to understand the graphic or passage. Even if you are unsure about the first one, try answering the rest of the questions—they may be easier for you.

### Experiment Skills

Experiments should be designed and conducted in accordance with the principles of the scientific method. This means that the goal of the experiment should be carefully formulated and the experiment should be set up to yield factual results. Review the concepts of the scientific method in the Science as Inquiry chapter if the tips included in this section are unfamiliar to you.

### Setting Up an Experiment

Experiments should be set up to test one clearly formulated and testable hypothesis. The number of variables (things changing) in the experiment should be limited and carefully controlled. If possible, experiments should contain a control group. For example, if you were to study the effect of a new soil supplement on house plants, the soil supplement should not be used on a few plants, which will comprise the control group. If there is improvement in the growth of only the plants on which the supplement was used, then there is strong indication that the supplement increases the plant growth. If, however, the plants in the control group grow as much as the plants on which the supplement was used, then the causes of growth most likely are not linked to the supplement. In this example, there would be two variables—1) the use of the supplement and 2) the plant growth.

How the supplement is administered and how plant growth is measured would need to be carefully described and controlled. For example, the scientist conducting the experiment would need to decide whether the supplement would be administered once, several times, or every day throughout the experiment. The scientist would also need to define what constitutes plant growth—the vertical increase, the number of new leaves, the growth of new branches and leaves, or some combination of these factors. One choice is not necessarily better than the others. Measuring the vertical growth wouldn't necessarily be worse than counting the number of new leaves. The important issue is to be consistent. If the number of leaves per plant is recorded on the first day, the number of leaves per plant should be recorded every day.

On the GED Science Exam, you may be asked to pick out the best design for an experiment. Before you look at the choices, determine what the important variables are, and think what would make a good control. Select the choice that contains the variables you thought of, that has the most logical experimental control, and in which the variables not studied are held constant.