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First of 2 part query: I have observed a 100 doctors and recorded the number of times they touch surfaces while in a room:

\begin{array}{l|c|c|c|c} \text{Dr number}&\text{Bed}&\text{Table}&\text{Chair}&\text{Door}\\ \text{Dr } 1&3&2&2&1\\ \text{Dr } 2&4&1&0&1\\ \vdots&\vdots &\vdots &\vdots &\vdots\\ \text{Dr } 100& 2&3&1&1 \end{array}

I would like to calculate the probability of him touching the Table for example. Would it be:

\begin{array}{l|c|c|c|c|c} &\text{Bed}&\text{Table}&\text{Chair}&\text{Door}&\text{Total}\\ \text{Average contacts}&3&2&1&1&\text{7}\\ P(\text{surface})&3/7&2/7&1/7&1/7&1 \end{array}

This is confusing me but I think a fresh pair of eyes will spot it instantly.

2nd part: I gave questionnaires out to some doctors who ticked boxes instead of giving contact numbers, i.e.:

\begin{array}{l|c|c|c|c} \text{Dr number}&\text{Bed}&\text{Table}&\text{Chair}&\text{Door}\\ \text{Dr} &\checkmark&\checkmark&\checkmark&\checkmark\\ \text{Dr } \checkmark&\checkmark&\checkmark&\times&\checkmark\\ \vdots&\vdots &\vdots &\vdots &\vdots\\ \text{Dr } 100& \checkmark&\checkmark&\checkmark&\checkmark \end{array}

What can I deduce from this table of ticks to compare with the table of exact values? Or is it not worth anything?

Please ask for any clarification if needed, Regards

EDIT: Revised Surface contact Probability Should this replace table 2?

\begin{array}{l|c|c|c|c|c} &\text{Bed}&\text{Table}&\text{Chair}&\text{Door}&\text{Total}\\ \text{Total contacts}&9&6&3&3&\text{21}\\ P(\text{surface})&9/21&6/21&3/21&3/21&1 \end{array}

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    I see. If the second table was of different procedures which were not observed by the researcher then do you think anything other than eg. 92 out of 100 Drs touched the table be deduced from it? Pop your comments in an answer and I'll give you a thumbs up. Cheers2012-05-05

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I think the only additional information you can gain from the second data set is whether there is a relationship between touching the table and touching other things. It also provides a comparison to your first data, to make sure neither sample varies far from the "true" proportion. However, taken by itself the only way I would tease a probability out if is by taking the proportion who touched a table.

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    That is what I think-although it would be worthwhile to check for relationships, I guess you have your numerical data to do that.2012-05-06