Damned right he has! - nothing like a quick downloaded, unreferenced, unexplained 9 year-old graph to sort things out eh? That's done the trick. Where is Pattaya on this scale?

Chon Buri is Pattaya (it is clearly marked) and the graph is dated 2009 although it begins in 2000. In other words, it is current and pretty easy to understand. Thanks; I thought that I was statistically-challenged

Too many assumptions. The graph on its own is not very intelligible. and should have been better presented. It reads "since 2000' and there's another date at the bottom - you ssume it presents data from 2000 up to 2009 - 2009 could be the date it was accessed/downloaded. Only reference to original source could determine that. 'Chonburi' could be the town not the province and the pollution levels could very well vary between Chonburi town (highly industrial) and Pattaya. If you make fewer broad assumptions then you might be less statistically challenged.

This goes to show that you have to be careful when you read ThaiVisa posts, some posters just don't have a clue what they're talking about

Good try, but pointless. Priceless is right.

Damned right he has! - nothing like a quick downloaded, unreferenced, unexplained 9 year-old graph to sort things out eh? That's done the trick. Where is Pattaya on this scale?

Chon Buri is Pattaya (it is clearly marked) and the graph is dated 2009 although it begins in 2000. In other words, it is current and pretty easy to understand. Thanks; I thought that I was statistically-challenged

Too many assumptions. The graph on its own is not very intelligible. and should have been better presented. It reads "since 2000' and there's another date at the bottom - you ssume it presents data from 2000 up to 2009 - 2009 could be the date it was accessed/downloaded. Only reference to original source could determine that. 'Chonburi' could be the town not the province and the pollution levels could very well vary between Chonburi town (highly industrial) and Pattaya. If you make fewer broad assumptions then you might be less statistically challenged.

This goes to show that you have to be careful when you read ThaiVisa posts, some posters just don't have a clue what they're talking about

A couple of comments: The graph is not "accessed/downloaded" from the Internet, it was derived on the date given (2009-06-15) from a database that I've built, consisting of data from the Pollution Control Department. It is based on all the (as of 12 June 2009) 8771 observations that the PCD have published since 1 January 2000 for Chiang Mai, Din Daeng and Chon Buri. Unfortunately I don't have access to the last four days of data, since the PCD website is down since Friday. Before you start counting the number of days since the beginning of this decade: Yes, there are days with missing observations, actually 19.8% for Chiang Mai, 9.7% for Din Daeng and 16.6% for Chon Buri. The data point in the graph with the lowest number of observations is for May in Chiang Mai with "only" 199 observations.

I do not have the exact location of the PCD measuring station in Chon Buri province, but in most cases they are located in Amphur Muang of each province. E.g. the Chiang Mai station is located near City Hall, approximately 6 kms NNW of the city centre. However, since there is a very limited number (less than 30) of measuring stations in Thailand, one has to make do with what there is. Pattaya is located in Chon Buri province, so I thought it reasonable to post the data for that province. The measuring station "Din Daeng" is located exactly where it says.

My sincere apologies for not including a complete explanation of every detail in my original post, but I have posted similar graphs many times previously and nobody has ever claimed to have had any problems understanding them before today. E.g. the word "since" has appeared to be perfectly comprehensible to earlier readers.

/ Priceless