LING571
Quiz #3
11/29/05
Your
name:
- (20
points) Let
- InsCost=DelCost=SubCost=1.0
- Ref
= “w1 w2 w3”
- Sys
= “w2 w1 w4 w3”
- (7
pts) Write down the array D[i][j]
w1 w2
w3
--------------------
|
0 1 2
3 |
w2 |
1 1 1 2
|
w1 |
2 1 2 2 |
w4 |
3 2 2 3
|
w3 |
4 3 3 2
|
---------------------
- (2
pts) What is the edit distance?
It is 2
- (3
pts) What’s the sequence of operations that turns Sys into Ref?
Del w2, and replace w4 with w2
- (8
pts) What are the values of WER? PER? SSA? GSA?
WER=2/3
PER=1/3
SSA=1-2/3=1/3
GSA=1-2/3=1/3
- (10
pts) Let
- Sys
= “a cat sat on the floor”
- Ref1
= “on the floor sat a big cat”
- Ref2
= “there was a large cat on the floor”
- (8
pts) What are unigram, bigram, trigram
precision?
p1 = 1.0, p2=2/5, p3=1/4
- (2
pts) What is the Bleu score, given N=3?
BLEU = e^{-1/6}
* (0.1)^(1/3) = 0.393