Simple "yes/no" script: help request!

You were super close! You just don't need the brackets around "Yes".
<pre style="width:630px;height:auto;overflow-x:auto;overflow-y:hidden;"
title="Copy this code and paste it into your Script Editor application.">

tell application "Finder"
 set my_file to the selection as alias
 set my_choice to button returned of (display dialog "Open This File with iDentify?" buttons {"Yes", "No"} default button 1)
 
 if my_choice is "Yes" then
 tell application "iDentify"
 activate
 open my_file
 end tell
 end if
end tell

</pre>

Hope this helps...

Two trivial changes I'd make - almost too trivial to mention but I can't resist... 🙂

set my_choice to button returned of (display dialog "Open This File with iDentify?" buttons {"Yes", "No"} default button 1)

The standard user interface puts the default action button to the right - look at any dialog in the OS and you'll see the 'cancel' button to the left and the (highlighted) 'ok' button to the right. To follow that model you should consider reversing your buttons:

set my_choice to button returned of (display dialog "Open This File with iDentify?" buttons {"No", "Yes"} default button 2)

(like I said, trivial, but anal 🙂 )

The second is a little more subjective.

You're relying on the selected items in the Finder. There could be one, or many items, and that select could include directories, volumes and files.

The line:

set my_file to the selection as alias

will fail if there are multiple items selected (you cannot make a list into an alias) or if there are no items selected.
Even if there is only one item selected you're not running any checks to see if your app can open them - I don't know what iDentity is supposed to do, so I don't know whether it will accept any file type (including directories) to know whether this is a problem or not.

For sure! Glad that was "Helpful".