Using Derwent Classification to improve your subject searching - Questel.Orbit Example
Search Tips - July 2000
This is a search for patents on antilock braking systems (ABS) for cars and other vehicles which illustrates how Derwent Classes can be used to overcome the problem of ambiguous search terms. We begin with a keyword search, which yields more than fifteen thousand records. This is an unexpectedly high number, so the next step is to display a few records in an inexpensive format to check what is being retrieved.
Begin searching in Derwent World Patent Index (Derwent WPI)
?fi dwpi
In this word search, "w" means that the search terms are adjacent to each other in the specific order.
?abs or ((antilock+ or anti lock+) w brak+) ** SS 1: Results 15.743
Display a few records in an inexpensive format to check relevance:
[for more details on display formats see Useful
formats for Derwent WPI]
?li titl 1-3
1/15743 DWPI - (C) Derwent
AN - 2000-399527 [34]
XA - C2000-120604
FS - CPI
DC - A18 A28 A82 G02
TI - Formulation for coating injection molded articles
contains random interpolymers
NP - 1
NC - 85
2/15743 DWPI - (C) Derwent
AN - 2000-399478 [34]
XA - C2000-120572
XP - N2000-299267
FS - CPI; EngPI
DC - A84 P77
TI - Ink-following plunger for ballpoint pen comprises
a stable gel with specified cone penetration
hardness
NP - 3
NC - 90
3/15743 DWPI - (C) Derwent- image
AN - 2000-399137 [34]
XP - N2000-299004
FS - EngPI; EPI
DC - P34 S05
TI - Adaptive brain stimulation device for treatment
of traumatic brain injury or brain dysfunctions,
performs statistical comparison between present
and reference state, to adjust stimulation
parameters
NP - 1
NC - 1
|
?li titl 53-54
53/15743 DWPI - (C) Derwent- image
AN - 2000-352934 [31]
XP - N2000-264447
FS - EngPI; EPI
DC - Q56 Q62 V06 X22
TI - Motor-pump device for use in a vehicle hydraulic
anti lock brake system has an eccentric and a
ball bearing inner race formed as a one-piece
tube-like integral component
NP - 3
NC - 3
54/15743 DWPI - (C) Derwent- image
AN - 2000-352562 [31]
XP - N2000-264199
FS - EngPI
DC - Q18
TI - Vehicle electro-hydraulic braking system delays
closure of travel simulator isolation valve until
at least two wheels are under ABS control
NP - 2
NC - 25
|
Large numbers of irrelevant records are being retrieved. The problem is the search term "ABS", which must be included in the strategy. However, ABS can also be an abbreviation for acrylonitrile-butadiene-styrene polymer and an abbreviation for antibodies.
Our search could be refined by incorporating further keywords such as cars or vehicles, but this would probably be too restrictive. The best way to overcome the problem is to confine the search to Derwent Class Q18 - Vehicle Brake Control Systems.
?1 and q18/dc ** SS 2: Results 3.201
Displaying a few records from search statement 2 in an inexpensive format:
[for more details on display formats see Useful
formats for Derwent WPI]
?li ss 2 titl 2-4
2/3201 DWPI - (C) Derwent- image
AN - 2000-394270 [34]
XP - N2000-296136
FS - EngPI; EPI
DC - Q18 X22
TI - Antilock brake system for motor vehicle, judges
failure frequency which is lower for vehicle
without parking brake compared to vehicle with
parking brake
NP - 1
NC - 1
3/3201 DWPI - (C) Derwent- image
AN - 2000-389151 [34]
XP - N2000-291402
FS - EngPI; EPI
DC - Q18 X22
TI - Vehicle braking system for controlling speed of
electrohydraulic braking comprises accumulator
and replenished by pumping additional working
fluid
NP - 2
NC - 25
4/3201 DWPI - (C) Derwent- image
AN - 2000-386331 [33]
XP - N2000-289154
FS - EngPI; EPI
DC - Q18 X22
TI - Integrated ABS, traction control, vehicle
stability control, braking system with a separate
boost valve has boost valve actuated by a
single solenoid
NP - 1
NC - 1
|
This is a good result - but can we do better? We can use MEMSORT to find out which Derwent Classifications have been assigned most frequently in this set of records. When using MEMSORT, if you wish to analyse the entire search set, which in this case is 3201 records, just type in "set". However, you can also analyse a smaller number of records, for example to analyse 500 records, type in "1-500".
?mems ss 2 set /dc Processing (1) Processing (2) Processing (3) Processing (4) Total number of terms extracted: 7970 Number of terms now in MEM2 : 94
Display the result of this analysis:
?li mems
Memory is of type MEMSORT (statistical analysis)
# FREQ TERM
1 3201 Q18
2 2512 X22
3 394 S02
4 376 Q13
5 146 T01
6 118 Q66
7 114 Q57
8 90 Q17
9 90 T06
10 79 V06
11 66 Q56
12 57 Q62
13 55 V02
14 54 Q63
15 53 Q22
Continue: Y / N
?n
From the result of our analysis we can see that X22 (Automotive Electrics) comes in second place. We can therefore bring X22 into our search as well. As can be seen from answer set "SS 3", we have considerably improved our search result by using both Derwent Classifications.
?1 and (q18 or x22)/dc ** SS 3: Results 4.143 ?li ss 3 titl 13-14
13/4143 DWPI - (C) Derwent- image
AN - 2000-367144 [32]
XR - 2000-334058
XP - N2000-274709
FS - EngPI; EPI
DC - Q18 Q57 Q66 X22
TI - Solenoid-controlled valve, e.g. for antilock
braking system, has two valves with opening/
closing modes varied in number of steps according
to displacement of movable part
NP - 1
NC - 1
14/4143 DWPI - (C) Derwent- image
AN - 2000-364823 [31]
XP - N2000-273046
FS - EngPI; EPI
DC - Q18 X22
TI - Anti-lock braking system brake operation
monitoring apparatus and method based on
calculating wheel speed differentials and
electronic control unit
NP - 1
NC - 23
|
?li ss 3 titl 22-23
22/4143 DWPI - (C) Derwent- image
AN - 2000-349865 [30]
XP - N2000-262117
FS - EngPI
DC - Q18 Q63
TI - A double action brake shoe has a lining and an
oscillator material, functioning as a
reinforcement of the brake shoe and as a
generator of certain vibration frequency when
the shoe is applied.
NP - 1
NC - 9
23/4143 DWPI - (C) Derwent- image
AN - 2000-345895 [30]
XP - N2000-260167
FS - EngPI; EPI
DC - Q18 Q56 X22
TI - Electrically operated pump for antilock brake
system of vehicle, has spring which presses
the reservoir to pass discharged fluid to pumping
section
NP - 1
NC - 1 |
Analysing Derwent Classifications is also a useful way of identifying a company's key activities. We will be looking at this in further detail in a Search Tip later this year.
For further assistance please contact your local Derwent Help Desk.