Unit 3: Chapter 1 - Science Inquiry

Question 1

Observations

Answer 1

In investigations based on observations, scientists are looking for patterns. When a pattern becomes clear it may be possible to draw conclusions. An example of an investigation based on observation is the discovery that peptic ulcers are caused by a bacteria infection. By using observations you can see the appearances of certain things and you can determine what they are or how they relate to a specific object.

Question 2

Controlled experiments

Answer 2

Often called fair tests, designed to investigate relationships between factors/variables. They involve changing one variable only and keeping all others the same. This is done to see if the changed variable has any influence in changing the other variables present in the experiment. Any differences in the results should be from the changed variable.
Eg. 8 mice all the same age and weight were injected with 100ml of a bacterium. 4 of the mice were put back into their cage and given no further treatment and the other 4 were given injections of penicillin.
Mice that were not given penicillin = control group
Mice that were given penicillin = experimental group

Question 3

Surveys

Answer 3

A process of systematically collecting, analysing, interpreting and organising data/information from usually a large group of people to conclude relationships and or information about the particular subject being surveyed. The information may be collected by a questionnaire or an interview. Using the large subject size, the person collecting the data can observe and look for patterns.

Question 4

Trial and error

Answer 4

Systematic process, can be random because it’s so repetitive and unclear. The process involves one attempt to solve a problem followed by another until a successful solution is proven to work effectively to produce the desired result or is proven correct.
Eg. Using trial and error, Thomas Edison examined over 600 different materials to use in a light globe before finding the one that was satisfactory. This process is often very tedious but is sometimes the only way to find effective substances.

Question 5

Case study

Answer 5

An in-depth investigation on one particular person or situation. They are frequently used in areas of business management and education. Also useful in some areas of science.
Eg. Medicine progress of a disease can be documented using a case to carefully examine the progress in great depth. Such case study can extend to help or confirm what is already known about the disease

Question 6

Longitudinal studies

Answer 6

A study conducted over a very long period of time. Similar to a case study but more prolonged. They may take place over many years even decades.
Eg. Busselton Health Study or fingernail growth.

Question 7

Scientific method

Answer 7

Scientists investigate in a methodical and systematic way. They usually collect quantitative data in the scientific method. The method created will be formed well to suit the problem present. Most will follow:
1. Recognise a problem and define and question.
2. Collect as much information as possible relating to the problem.
3. Propose a hypothesis, a possible explanation to the problem.
4. Test the hypothesis using an experiment.
5. Analyse and interpret the data collected from the experiment.
6. Draw conclusions about whether the hypothesis was supported or disproved.
7. Report on the investigation.
Presenting the findings can be done using a graph or stating a well planned conclusion. The results of an experiment can not prove the experiment but can support it only.

Question 8

Literature review

Answer 8

A survey of the material that has been written about the subject under consideration. Created by research from the internet.
Purposes:
To help the researcher define the problem.
To help the reader discover what is already known about the problem to prevent duplications of already conducted experiments.
To assess research methods.
To allow the researcher to relate their findings to what is already known about the subject for conclusions and final reports.

Question 9

Safety

Answer 9

Assessing your experiment to make sure it poses no risks to the people participating in the experiment. If so you must consider safety devices such as eye washes, fire extinguishers, fire blankets and flame hoods. Also you most consider safety equipment such as safety glasses, gloves, lab coat and other safety measures. You most also make sure the subjects participating in the experiment have no safety health risks that may be affected by the experiment such as allergies or conditions. Lastly you must create the experiment environment to be safe and welcoming so the people do not feel unsafe, embarrassed or threatened.

Question 10

Ethics

Answer 10

A set of moral principals or values. Ethical behaviour is the behaviour that follows those values. In experiments or research involving human participants, there are many ethical issues that must be taken into consideration.
Voluntary consideration - individuals must not feel pressured to participate in the investigation.
Informed consent - the individuals must be properly informed about the aspects of the experiment and the research involved as well as the risks that may be involved in the investigation, consent should only be given after all information has been told.
Risk of harm - there should be no risk of physical or psychological harm.
Confidentiality - the identities of participants should not be revealed except people directly involved in the study.

Question 11

Variable

Answer 11

Any factor that may change during an experiment

Question 12

Independent variable

Answer 12

The factor being investigated; deliberately changed to determine its effect. This variable is deliberately made different in the control and experimental groups in an experiment. By comparing the results from the control and experimental groups, the effect of the independent variable can be determined.
Plotted on the horizontal axis (x)

Question 13

Dependent variable

Answer 13

The variable that changes as a result of the effect the altered independent variable has on the dependent variable.
Plotted on the vertical axis (y)
What we measure

Question 14

Controlled variables

Answer 14

Variables that are kept the same in both control and experimental groups throughout the whole experiment. There are usually measures put in place by the participants to make sure the desired controlled variables are kept constant. If these aren’t kept the same, it is nearly impossible to determine which variable had the effect on the dependant variable.

Question 15

Uncontrolled variables

Answer 15

Sometimes it is impossible to keep variables the same during an experiment. They may have been missed by the experimenter or impossible to keep the same. If these variables are present in an experiment, they must be considered when interpreting the results.

Question 16

Repetition

Answer 16

Doing the experiment many times. Helps to demonstrate that the results are consistent. Increasing the number of times you perform the experiment increases the value. Makes the experiment more reliable

Question 17

Replication

Answer 17

Having a number of identical experiments running together of performing the experiment on a large number of subjects at the same time. Help to demonstrate that the results are consistent. The more times you perform the same experiment, the more value it has. Makes the experiment more reliable

Question 18

Validity

Answer 18

To which extent the experiment tests to what it’s supposed to test. Experiments can be invalid if there are uncontrolled variables.
Testes hypothesis
Results link to what you’re trying to test
Sometimes not all variables can be controlled eg. Organisms

Question 19

Reliability

Answer 19

The extent to which an experiment gives the same result each time it is performed. The measuring instruments used in the experiment must be reliable to produce consistent results.
Eg. If a set of scales gives three different weights each time you step on them, they are considered unreliable and if used in an experiment would make the results unreliable.
Using massive sample sizes and doing lots of trials

Question 20

Errors

Answer 20

Errors in experiments are any deviations from the result that should have been obtained. 
Random errors
A measurement or instrument error
Systematic error 
Something wrong with the setup

Question 21

Measurement error

Answer 21

Measurements made with any measuring instrument are only approximate. This is use to the human vision and perception of measurement placements and reading.
Eg. Measuring a persons height and getting many different results each time occurs as a result of natural variation in the subject, variation in the measurement process, or both.
Repetition can be used to reduce measurement error but can not overcome error.

Question 22

Limitations of data

Answer 22

Drawing conclusions that give invalid information beyond the data. Some scientists draw conclusions that are not necessarily supported by their data.
Eg. A survey showed that the incidence of breast cancer in women who exercised regularly reduced by 37%. The media reported on the investigation with the headline “Exercise Prevents Breast Cancer”.

Question 23

Secondary data

Answer 23

Data collected by someone other than the individual(s) using the data

Question 24

Confidence interval

Answer 24

Used to indicate the reliability of the data. It is the range of values above and below a result in which the actual value is likely to fall.

Question 25

Confidence level

Answer 25

The most common confidence level used in research is 95%, this means if the research were repeated a number of times, the range of values obtained would contain the true value 95% of the time

Question 26

Percentage change

Answer 26

New value - old value/Old value x 100

Question 27

Probability

Answer 27

The number of ways an event can occur divided by the number of possible outcomes

Question 28

Graph

Answer 28

Shows how changes in one variable affect another variable

Question 29

Model

Answer 29

A simplified representation of an idea or process. Can be applied to and relate many situations/investigations. May be a diagram, a flow chart or a physical model. Scientific models are often modified as new data is collected.

Question 30

Flow chart

Answer 30

A diagram that shows the steps involved in a process

Question 31

Report

Answer 31

A scientific report includes a description of the investigation, the results obtained and any conclusions drawn from these results. The description must allow enough information for another person to repeat the experiment.

Question 32

Scientific report format

Answer 32

Title
Introduction: nature of the problem and hypothesis
Materials and Equipment
Procedure
Results: often presented as tables, graphs diagrams or photos
Discussion: comments about the results and the way they relate to the hypothesis that was tested
Conclusion
Further research: scientific reports raise more questions then they answer
References
Acknowledgment

Question 33

Blind test

Answer 33

Subjects to not know if they are receiving the drug or placebo
Benefits: if you think you are taking the drug you may have different effects than thinking you’re taking the placebo

Question 34

Double blind test

Answer 34

Both subjects and scientists don’t know who is receiving the drug or who is receiving the placebo. The scientists would only find out during analysis.
Benefits: avoid bias, may treat people differently

Question 35

Accuracy

Answer 35

How close a measurement is to its true value. An accurate measurement includes an estimate of a true value, and an estimate of the uncertainty.
Uncertainty is a result of error in the experiment.

Question 36

Percentage error

Answer 36

Absolute error of instrument/measurement value

Question 37

Graphs

Answer 37

Use line for quantitative data

Use bar for qualitative data