# a2 SNAB BIOLOGY COURSEWORK watch

1. help me
can some one tell me what the critical value is for the spearmans rank corellation coefficient?

mine is -0.617489177

2. (Original post by xshopoholicx)
help me
can some one tell me what the critical value is for the spearmans rank corellation coefficient?

mine is -1.68398268

because your value is negative it would mean that there is negative correlation between the two variables that you are testing
3. (Original post by xshopoholicx)
help me
can some one tell me what the critical value is for the spearmans rank corellation coefficient?

mine is -1.68398268

It depends on how many readings you have for a start, it also depends on how accurate you want to be... for A level biology 95% accuracy is usually fine which translates to 0.05 on the tables. Essentially more readings mean a lower score is needed to be significant.

Also spearman's rank values are usually between a range of 1 and -1, you sure you didn't do the test wrong?

Anyhow heres the table for 5%, value on the left being number of results and value on the right being the value needed for spearman's rank to be significant:

5 1.00
6 0.94
7 0.89
8 0.83
9 0.78
10 0.75
11 0.73
12 0.71
13 0.67
14 0.64
15 0.62
16 0.60
17 0.58
18 0.56
19 0.55
20 0.53
21 0.52
22 0.51
23 0.50
24 0.48
25 0.47
26 0.46
27 0.46
28 0.45
29 0.44
30 0.43

If the number is negative still use the table but remember it is a negative correlation and not a positive one.
4. (Original post by Wallam)
It depends on how many readings you have for a start, it also depends on how accurate you want to be... for A level biology 95% accuracy is usually fine which translates to 0.05 on the tables. Essentially more readings mean a lower score is needed to be significant.

Also spearman's rank values are usually between a range of 1 and -1, you sure you didn't do the test wrong?

Anyhow heres the table for 5%, value on the left being number of results and value on the right being the value needed for spearman's rank to be significant:

5 1.00
6 0.94
7 0.89
8 0.83
9 0.78
10 0.75
11 0.73
12 0.71
13 0.67
14 0.64
15 0.62
16 0.60
17 0.58
18 0.56
19 0.55
20 0.53
21 0.52
22 0.51
23 0.50
24 0.48
25 0.47
26 0.46
27 0.46
28 0.45
29 0.44
30 0.43

If the number is negative still use the table but remember it is a negative correlation and not a positive one.
sorry the spearmans rank is -0.617489177 and i need it to be a 95% significance
5. (Original post by xshopoholicx)
sorry the spearmans rank is -0.617489177 and i need it to be a 95% significance
How many readings did you use?

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 31, 2011
Today on TSR

### University open days

• University of East Anglia (UEA)
Could you inspire the next generation? Find out more about becoming a Secondary teacher with UEA… Postgraduate
Thu, 18 Oct '18
• University of Warwick
Sat, 20 Oct '18
• University of Sheffield