# Weights
You can add the *weight* attribute to an element. Weight is a positive floating point value that represents the degree to which the phrase in the item is boosted during speech recognition. For more information, see [Weights](https://www.w3.org/TR/speech-grammar/) in the Speech recognition grammar specification version 1 W3C recommendation.
Weights must be greater than 0 and less than or equal to 10, and can have only one decimal place. If the weight is greater than 0 and less than 1, the phrase is negatively boosted. If the weight is greater than 1 and less than or equal to 10, the phrase is positively boosted. A weight of 1 is equivalent to giving no weight at all, and there is no boosting for the phrase.
Assigning appropriate weights to items for improving speech recognition performance is a difficult task. Here are some tips you can follow for assigning weights:
+ Start with a grammar without item weights assigned.
+ Determine which patterns in the speech are frequently misidentified.
+ Apply different values for weights until you notice an improvement in the speech recognition performance, and there are no regressions.
**Example 1**
For example, if you have a grammar for airports, and you observe that *New York* is frequently misidentified as *Newark*, you can positively boost New York by assigning it a weight of 5.
```
id="airport">
-
Boston
out="Boston"
-
New York
out="New York"
-
Newark
out="Newark"
```
**Example 2**
For example, you have a grammar for the airline reservation code starting with an English alphabet followed by three digits. The reservation code most likely starts with B or D, but you observe that B is frequently misidentified as P, and D as T. You can positively boost B and D.
```
id="alphabet">
- Aout.letters+='A';
- Bout.letters+='B';
- Cout.letters+='C';
- Dout.letters+='D';
- Eout.letters+='E';
- Fout.letters+='F';
- Gout.letters+='G';
- Hout.letters+='H';
- Iout.letters+='I';
- Jout.letters+='J';
- Kout.letters+='K';
- Lout.letters+='L';
- Mout.letters+='M';
- Nout.letters+='N';
- Oout.letters+='O';
- Pout.letters+='P';
- Qout.letters+='Q';
- Rout.letters+='R';
- Sout.letters+='S';
- Tout.letters+='T';
- Uout.letters+='U';
- Vout.letters+='V';
- Wout.letters+='W';
- Xout.letters+='X';
- Yout.letters+='Y';
- Zout.letters+='Z';
```