Graphs and Scientific Method Flashcards
What is the aim?
Contains dependent and independent variables
Examples: To show that… To observe… To determine…
What is the difference between the independent, dependent and the fixed variables?
The variable that can be changed by the scientist is independent, the variable that changes in response to the independent variable is dependent and the variables that have to stay the same every time you do the experiment to make sure its valid are fixed.
What is a hypothesis?
What you predict will happen, like the aim it has to include the dependent and independent variables
How can you make your experiment more reliable?
- Repeat the experiment
- Take lots of readings and use the average
- Select a random sample
- Increase the sample size
- Increase the period of the experiment
NB!! Not all of these will apply to your experiment, check which ones will work
What is validity and how can you make your experiment valid?
Validity questions how the experiment was carried out. To make an experiment valid you need to make sure your fixed variables remain constant. (If asked in an exam just give examples of fixed variables)
How do you work out percentage increase?
Difference between two given numbers / first number x 100
EXAMPLE: Rainfall in January was 25ml and 82ml in June. Calculate percentage increase.
(82 - 25 / 25) x 100 = 228%
What is a line graph?
It is a graph that’s used for displaying data or information that changes continuously over time (eg. rainfall)
NB!! Only connect to 0;0 if that’s one of the points
What is a histograph?
They are used to represent continuous data. You will get told in exams if you need to draw one. There is only a gap between the bars and the y-axis, nowhere else
What is a bar graph?
They are used to represent grouped data or different categories (Age, shoe size). The bars don’t touch each other
What is a pie chart?
A type of graph in which a circle is divided into sectors that each represent a proportion of the whole. Use protractors to draw
How do you figure out the degrees for each part of the pie chart?
number / total x 360
EXAMPLE: 55 out of 270 vehicles are vans
(55 / 270) x 360 = 73 degrees
What are the biological drawing rules?
Draw in pencil
Label lines and labels in pen
Label lines don’t cross, end at same point, drawn with ruler, on the right hand side
Detailed, underlined caption underneath
What are the drawing graph rules?
x-axis is the independent variable
y-axis is the dependent variable
Scale goes up in regular intervals
Use // in scale if first no. is big
Heading always starts with “A (type of graph) showing…”
Heading must be underlines and contain both variables
Draw a key if there is multiple lines/bars
