Letter writing analysis
Questioned Document Examiners use several methods of comparison to ensure the accuracy of their analysis.  Computers have increased the efficiency of the comparisons because sample signatures can be scanned in and overlayed.  Computers can also store samples for later comparisons.  You will do four different common techniques. 

Each person has an unique handwriting style.  The following series is one set of techniques used to identify each person's style.  Do this analysis for yourself.

1.  Write your name two times on a sheet of white paper.

2.  Place a piece of notebook paper over the signature.

Top-of-Letter

3.  Make a small mark on the notebook paper at each of  the high points of each letter in both signatures.  In other words, note how high each letter goes.

4.  Use a ruler to join each mark to the one next to it, creating a ziazag line across the top of each signature.

5.  Compare both zigzag lines.  Are they similar?  Why?

Bottom-of-Letter

3.  In a new area, make a small mark on the notebook paper at each of  the low points of each letter in both signatures.  In other words, note how low each letter goes.

4.  Use a ruler to join each mark to the one next to it, creating a ziazag line across the bottom of each signature.

5.  Compare both zigzag lines.  Are they similar?  Why?

6.  Have a friend or parent forge your signature 1-2 inches below your real signature and make top and bottom of letter comparisons of the forged signatures.

     a.  How do the forged lines compare to the authentic signatures? (You will have to fill out the form at the bottom.)

     b.  Could this method of analysis prove that your helper's signature was a forgery?  How so?

Spacing Analysis

3.  Make a small mark on the notebook paper at all of  the low points of each letter in both signatures.  You are noting the beginning and end of each letter.

4.  Use a ruler to join the rightmost mark or each letter to the leftmost mark of the letter next to it.  (You skip the first mark and connect the next pair.  You connect each pair after that.  You may have one mark left at the end.)  This creates a series of short lines.

5.  Compare the series of  lines.  Are they similar?  Why?

Slant Analysis

3.  Make a small mark on the notebook paper at each of the high and low points for each letter, such that each letter has a mark on top and a mark on bottom.

4.  Use the ruler to join each high point to each low point for every letter.  This will give you a slanted line for each letter.

5.  Compare the series of slanted lines.  Are they similar?  Why?

6.  Using your helper's forged signature, make spacing and slant comparisons of the forged signatures.

     a.  How do the forged lines compare to the authentic signatures? (You will have a form to fill out the answer.)

     b.  Could this method of analysis prove that your helper's signature was a forgery?  How so?

Fill out the form for each question.

How did the top of letter analysis compare for the two authentic signatures? 
How did the top of letter analysis compare with the forged signatures and authentic signatures?