File:  callinfo.doc
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   Explanation of the audit information provided in "callinfo.tbl"

The file "callinfo.tbl" contains the information produced by manual
auditing of the Switchboard-2 Phase II conversations.  The auditing
process was set up to accomplish two things: (a) provide information
about the speaker and (b) provide information about the channel
quality for the conversation.

The table file contains a single line for each side of a conversation
with comma separated fields to provide the following information:

Field 1=file name
Field 2=date
Field 3=participant PIN
Field 4=channel
Field 5=echo/crosstalk
Field 6=background noise
Field 7=distortion
Field 8=comments (if any)

EG: 970125,3196,B,0,0,0,"call_waiting_minute_5"

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The following information is provided:

- the file name (sw_11545.sph)

- the date the call was recorded (960508) 

- the caller's PIN number (1288)

_ whether the participant initiated the call or was a callee
(A=initiated, B=callee) 

- information regarding: echo/crosstalk, background noise, distortion
and length of call (2=some echo, 0=no discernible background noise,
2= distortion, 0=call not empty, for variants see below)

- auditor comments (call_waiting_answered_minute_2)

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The information on echo (echo or crosstalk in the telephone circuit
refers to the audibility of the channel A speaker in channel B and
vice-versa), background noise (refers to the amount of sounds not made
by the speakers, e.g. baby crying, television, radio, etc.),
distortion (refers to echo and other types of recording problems) and
empty (duration of call) should be interpreted as follows:

- for echo, background noise and distortion: 0=none, 1=discernible, 2=moderate,
3=excessive 

- auditor comments (e.g.s include: "cordless_phone", "television",
"static", "phone_hum")


All attributes are thus rated on a scale of 0 to 2, where 0 always
refers to optimal channel/call conditions and 2 refers to the least
optimal, but still usable channel conditions.