Google keyword tools show different results

Hello,
right now i'm in the stage of getting keywords for my new SEO campaign, which is the hardest part i believe.
I tried to get results for a selected keywrod from 'search-based keyword tool' by Google, it returned 23,000 as monthly searches, while Google adwords keyword tool returns 301,000 as local monthly searches (USA). There is a big gap between these figures. Anyone know what's going on?

Thanks!

PS: url for search-based is : http://www.google.com/sktool/

 

Google talk
"...
You may also notice that some of the data (like such as the monthly search volume) may vary slightly between the two tools, which is due to different methods of calculation at this time.
"

 

Only if you knew how to search for help:

Google Adwords Tool Vs Search Based Tool

 

Thanks for you guys. I understand the data may vary slightly between these tools. but in my case it's 10 times more between each tool.
Thanks!

 

Hi
thats why i prefer other tools..
Semrush generally.

 

Try to use long tail keywords with less competition - use keywords that consist of at least three words as they will be more targeted.

 

i only use google adwords kw tool. i never bother with anything else

 

These are automated systems which gives result on last search base, now it's result old so you see different result.

 

Ohh, but i am using Google Adword and no anyone and it's a new thing for me that Different Keyword Tool showing different results.