Working Scientifically Flashcards
What is an observation?
When an object or process is looked at carefully
What is an investigation?
An experiment or set of experiments designed to produce data to answer a specific question or test a theory
What is data?
Words or numbers that you obtain when you make observations or measurements
What can an observation do?
Give you an idea that you can test in an investigation
What questions can be asked about refridgerated tennis balls?
- How does the size of a ball affect how high it bounces?
- How does the temperature of a ball affect how high it bounces?
What is a variable?
- Anything that might affect the outcome of an investigation
- The things that are affected as a result of the change
What is an independent variable?
A variable you change that changes the dependent variable
What is a dependent variable?
A variable that changes when you change the independent variable
What is a control variable?
A variable that you have the keep the same in an investigation
What is a prediction?
A statement that says what you think will happen that is backed up using scientific knowledge
What should a plan include?
- The scientific question you are trying to answer
- The independent and dependent variables
- A list of variables to control and how you will do it
- A prediction
- List of equipment
- A risk assessment
- What you will use to collect accurate and precise data
What is a plan?
A description of how you will use equipment to collect valid data to answer a scientific question
What is accurate data?
Data that is close to the true value of what you are trying to measure
What is precise data?
Data that gives similar results if you repeat the measurement
What is a spread?
The difference between the highest and lowest measurements of a set of repeat measurements
How much spread does precise data have?
Not much when measurements are repeated as they are closely grouped together
What is uncertainty and why does it occur?
The doubt in a result because of the way that a measurement is made
When is data repeatable?
When an investigation, or measurement, is repeated serveral times but still show similar outcomes
When is data reproducible?
When other people carry out an investigation and get similar results to the original investigation
What is continuous data?
It can have any data, such as length or temperature
What is discrete data?
It can have only whole-number values, such as number of paperclips or woodlice
What is categoric data?
When the data is a word, such as ‘blue’ or ‘hot’
What measurements can you test?
- The biggest and smallest - this is the range
- How many different measurements you can test
What is a risk assessment?
A description on how you will make it less likely that people will be injured, or equipment damaged, and what to do if this happens
What is an outlier?
An anomalous result that is very different to the others
When should you plot a line graph?
If both the independent and dependent variables are continous
When should you plot a bar chart?
If the independent variable is categoric
When should you plot a pie chart?
When you have discrete or categoric data
What variables should go on each axis?
Independent - x axis, dependent - y axis
Why are line graphs important?
It helps you to spot a pattern; how the dependent variable depends on the independent variable
What is an analysis?
The process of looking at data and writing about what you have found out
What is a line of best fit?
A line that goes through as many points above or below the line; ignores any outliers
What is a conclusion?
What you write down to say what you have found out during an investigation
What should you include in a conclusion?
What you have found out - what does the investigation show and any relationship between the two variables
Explain what you found out - Use scientific knowledge to explain the pattern as well as comparing your results with your prediction
How can you evaluate your investigation?
- Discuss the quality of the data that you have collected
- Suggest and explain improvements to your method so you can collect data of better quality if you did it again
What is confidence in a conclusion?
How sure you are of your conclusion based on the data
When would you have less confidence in your conclusion?
If there were lots of outliers
When would you have more confidence in your conclusion?
If there was a small spread in the data, e.g. measurements for one temperature do not overlap with the measurements for another
What types of error can affect scientific measurements?
Random and systematic
What is a random error?
An error that can affect the speed, or cause outliers, e.g. the temperature of the room suddenly changing because someone opens a door
What is a systematic error?
An error that can make your measurements less accurate, e.g. a newtonmeter reading 1N even when there is nothing attached to it
What other factors can be used to explain your confidence?
Possible errors, outliers and spread
How can you get better data?
- Including a bigger range, or taking more readings
- Using different apparatus - giving a smaller spread and fewer outliers
What is a hypothesis?
An educated guess, or a guess based on information you already know
What should you do when testing the hypothesis?
Make a prediction based on the hypothesis and test it
What is validity?
How well a test measures what it is supposed to measure
What should valid results be like?
Repeatable, reproducible and answer the original question
What is an example of representive data?
If your sample is representative of the entire population you will be able to confidently generalise the results of your study to that population
How should a conclusion start?
As the independent variable changes, the dependent variable increases/decreases/stays the same
What is an example of a conclusion drawn from a graph?
- As the pH increased the time for no starch to be detected decreased
- up to 7.0 pH where it was 1.5 mins
- after pH 7.5 the time increases again
