Practical Skills Study Sheet

Hypothesis

An explanation of an observation that can be tested through experimentation.

Variable

A condition in an experiment that can be controlled or changed.

Theory

A well-substantiated explanation of an aspect of the natural world that has been repeatedly tested and confirmed through observation and experimentation.

Qualitative Data

Descriptive data about a variable.

Quantitative Data

Numerical data that defines the quantity, amount, or range of a variable.

Prediction

A statement of the expected results in an experiment based on the hypothesis being tested.

Independent Variable

The variable being changed in an experiment.

Dependent Variable

The variable being measured in an experiment.

Control Group

A group within an investigation that receives the same treatment as the experimental groups except for the variable being tested.

Random Error

An error in measurement caused by factors that vary from one measurement to another.

Control Variables

Variables that are not being tested but must be kept the same to avoid affecting the experiment.

Confounding Variables

Variables that could affect the independent or dependent variable and therefore the results of the experiment.

Water Bath

A container of water heated to a given temperature used to vary or control temperature.

Buffer

A solution that can maintain a relatively stable pH.

Reliable

Results that can be replicated by other people.

Anomaly

A result or observation that deviates from what is normal or expected.

Precision in Measurement

The level of refinement in a measurement as shown by the number of significant figures given.

Precision in Experiment

Refers to the closeness of the measurements to each other.

Accuracy

Ensuring that measurements are close to the true value.

Line Graph

A graph drawn to show the relationship between two continuous variables.

Histogram

A graph drawn to show the frequency of one continuous variable.

Bar Chart

A graph drawn to show the relationship between one continuous and one discontinuous variable.

Continuous Variable

A variable that can take any value.

Discontinuous Variable

A variable that can only take certain values.

Systematic Error

A consistent error affecting each measurement in the same way, often due to faulty equipment.

Random Error

An error in measurement caused by factors that vary from one measurement to another (repeated definition).

X-Axis

The axis on a graph where the independent variable is placed.

Y-Axis

The axis on a graph where the dependent variable is placed.

T or F?: You should give each axis a descriptive label, but you do not need to include units.

False.

T or F?: When plotting a line graph, you can use a small x or small dot, but not both.

True

T or F?: In a bar chart, the bars should have gaps between them, drawn using a ruler, and the gaps between the bars do NOT have to be evenly space, but the bars should be the same width.

False

T or F?: In a histogram, the bars should have gaps between them, drawn using a ruler, and the bars should be the same width

False

T or F?: You should join the points of a line graph with a ruler unless you have been asked to draw a line of best fit

True

T or F?: If your graph is a line of best fit then try to make sure there are the same number of your plotted points on either side of the line.

True

Anomalous Data

Identify readings that do not fit the pattern during evaluation procedures.

T or F?: There can still be sources of error even without anomalous results.

True

Control Variables Check

Check measurements of control variables for potential anomalous results.

Procedure Improvements

Use evaluation to suggest improvements for more accurate and reliable results.

T or F?: When carrying out any calculations, it is NOT necessary to show all of your work.

False

Descriptive Statistics

Use range, standard deviation, and standard error to simplify data and assess variability.

Conclusion Writing

Describe the relationship between the dependent and independent variable in a conclusion.

T or F?: When writing a conclusion you should link back to your hypothesis and prediction but it is NOT necessary to describe whether the hypothesis has been supported.

False

T or F?: Suggest further questions for investigation and predict results in the conclusion.

True

Digital Thermometer

The most accurate way to measure temperature.

Types of Hazards

Include corrosive chemicals, glass equipment, and hot equipment.

pH Probe

The most accurate way to test pH.

Volume Measurement

Use a measuring cylinder, pipette, or syringe to measure volume.

Short Distances

Should be measured in centimeters.

Longer Distances

Should be measured in meters.

T or F?: Part of the experimental planning summary includes working ethically to avoid harm with living

True