1. A method to evaluate sources
What is OPVL?
A method to evaluate sources

2. Origin What is it? When was it produced? Where does it come from?
Who produced it?

3. Purpose Why was it produced?
Think about who the audience was (who was this source for?)

4. Value What is the value of the source to an Historian?
This is derived from the Origin & Purpose

5. Limitations
The problems or difficulties associated with the source. Comes from the Origin & Purpose.
lacks detail
over-simplified
important parts missing
includes bias
may have been changed or altered in some way

6. Summary
What
When
Value
Origin
Where
Limitations
Who
Why
Purpose

7. Have a Go!
This is an extract from the diary of a soldier in the First World War:
29th. Dec. Front Line again. What an affection it has for us! Heavy journey with two days rations. The going was so hard it took an hour for the party to move 3/4 of a mile. None of my men fell out, but I've had more trouble with the sergeant. He'll go at the first opportunity! Mud a tremendous hindrance. It prevented large patrols going out. Hun (English nick name for the Germans) did not seem to worry.
Farquharson and I were nearly shot by one of our own Lewis Gun men while taking a walk in "No Man's Land". (We had gone out without warning ALL our front line men. By chance the gunner got a glimpse of my bare knees and kilt, and recognized we were not Huns).
30th. Dec. Longest day in my life so far. Could not move about. All the trenches had fallen in, and our men just lay about in shell holes. The Hun treated us to aerial darts and grenades and we had a few casualties, chiefly in my platoon.
Written by: Robert Lindsay Mackay - Somme, France, 1916 from his wartime diaries.