error bars

anyone know what an error bar is?

wikipedia doesnt explain how to draw them/polt them...

any help would be greatly appreciated - the edexcel biology as coursework mark scheme specifically asks for error bars....

THANK YOU

Reply 1

dh00001

an error bar is basically a point of the graph about where the point could potentialy lie. so if theres an error of 5% you would have the average or calculated value. a line up 5% and a line down 5%. does that help because its just a brief description

Reply 2

rich_rob

it kinda helps, but how do i work one out and put it on a graph?

Reply 3

Sarah_V

the way we did it for our A2 bio coursework was:
plot the average, then we plotted the maximum value recorded above this point, and the minimum value below it. You then just join them together basically.
Well, that's what we did anyway...

Reply 4

dh00001

yea thats a simple way of doing it. which if i remember rightly is fine for bio

Reply 5

iainmacn

yeah that's how we did it too - sort of a capital I (with serifs) shape with a cross at the mean

Reply 6

rich_rob

thanks a lot guys - you've saved me from losing some crucial marks!

Reply 7

super'girl

i remember it saying : errors bars where necessary
u dont have to do them unless it would be appriopiate if so

Reply 8

josie!!!

if you plot error bars, do you also plot anomalous results? (as part of the error bars i mean.)

Reply 9

Hannah_Jeffries

Is it the bigger the line the higher the error as you've got a big range in your results ??

I now remember my teacher talking about this and i didnt put it on my courseowrk :frown: