Analytical Variation

Question 1

chance / unpredicatable cause
does not recur

Answer 1

random error

Question 2

one-time error

Answer 2

random error

Question 3

affects precision;
violation of 1^2s, 1^3s, R^4s

Answer 3

random error

Question 4

recurring error

Answer 4

systematic error

Question 5

affects all results

Answer 5

systematic error

Question 6

affects accuracy; indicated by shift, trend or 2^2s, 4^1s, 8^1s, 10x̄

Answer 6

systematic error

Question 7

abrupt change
accumulate on one side
6 consecutive days

Answer 7

shift

Question 8

gradual change
increase or decrease for 6 consecutive days
passing through mean

Answer 8

trend

Question 9

highly deviating control values caused by random or systematic errors

Answer 9

outliers

Question 10

mean; y axis
run number; x axis

Answer 10

CUSUM chart

Question 11

interlab comparison of monthly means

Answer 11

Tonks-Youden plot

Question 12

most commonly used QC chart

Answer 12

Levy-Jennings chart

Question 13

1 ctrl value exceeds ±2SDs
warning rule
initiates testing of other rule

Answer 13

1-2s

Question 14

1-2s
error detected:
decision:

Answer 14

error detected: imprecision
decision: accept run

Question 15

1 ctrl value exceeds ±3SDs

Answer 15

1-3s

Question 16

1-3s
error detected:

Answer 16

imprecision/ systematic bias

Question 17

range between 2 levels of control with a run exceeds 4SDs

Answer 17

R4s

Question 18

R4s
error detected:

Answer 18

imprecision

Question 19

2 consecutive values of 2 qc samples exceed 2SDs same direction

Answer 19

2-2s

Question 20

2-2s
error detected:

Answer 20

bias (inaccuracy)

Question 21

4 consecutive control values exceed 1SD

Answer 21

4-1s

Question 22

10 consecutive values same side of the mean

Answer 22

10x̄

Question 23

4-1s and 10x̄
error detected:

Answer 23

bias trend

Question 24

what to do during 1-3s, R4s, 2-2s, 4-1s and 10x̄

Answer 24

reject run
troubleshoot
rerun
when in ctrl -> release result

Question 25

8 consecutive values exceed 1SD same direction

Answer 25

8-1sc

Question 26

cumulative sum of SDI

Answer 26

CUSUM

Question 27

exponentially weighted moving average

Answer 27

EWMA

Question 28

2 out of 3 control values exceed the same mean ±2SDs

Answer 28

2 of 3-2s

Question 29

3 consecutive control exceed same mean ±1SD

Answer 29

3-1s

Question 30

6 consecutive control values are on the same side of the mean

Answer 30

6x̄

Question 31

8-1s, CUSUM, EWMA
error detected:
decision:

Answer 31

bias trend
reject run

Question 32

2 of 3-2s, 3-1s, 6x̄
error detected:
decision:

Answer 32

3 levels of control: REJECT RUN