I studied fluoride release of 5 different filling materials by making 10 disks of each material (Total 50). The journal editor wants me to calculate sample size. What I know is sample size is calculated for clinical, in vivo and etc studies to save lives. In my case how should I calculate sample size?
Thanks
You are right. You can use to get an automated size for regular clinical studies or calculate using standard formulae specific to study design/type.
I believe you are right but please see what other researchers say-- especially those in statistics/public health. Once you gather your evidence,You need to educate the editor with evidence to show that what you have done is correct. BUT be sure to present evidence to prove it!
Editors are NOT always right....
Cheers!!
One can estimate the sample size using either power analysis or the resource equation method. The sample size for In vitro studies usually is calculated using the latter method, which is based on the law of diminishing return. This is the method of choice most of the times because in vitro studies involve several groups, interactions, variables, etc. You can get detailed information about how to calculate the sample size using those methods in the following links:
http://www.ncbi.nlm.nih.gov/pubmed/11506638
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3826013/
Good luck!
to do power analysis to estimate your sample size, you have to write your hypothesis, and based on that you decide what statistical test you will use. It should be one of the inferential statistics. so you need to determine the following: alpha {standard to be .05}, power [standard to be .80], effect size {small, moderate, or large, each test has its own value, you can find these values in the net}. Then download free programs to calculate the sample size such as G. power.
Dear RG colleague,
Determining the sample sizes involve resource and statistical issues. Usually, researchers regard 100 participants as the minimum sample size when the population is large. However, In most studies the sample size is determined effectively by two factors: (1) the nature of data analysis proposed and (2) estimated response rate.
For example, if you plan to use a linear regression a sample size of 50+ 8K is required, where K is the number of predictors. Some researchers believes it is desirable to have at least 10 respondents for each item being tested in a factor analysis, Further, up to 300 responses is not unusual for Likert scale development according to other researchers.
Another method of calculating the required sample size is using the Power and Sample size program (www.power-analysis.com).
Regards,
- Badges
- Science topic
- Similar topics
- Mathematics
- Statistics
- Sampling Design
- Sample Size