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SCHEDULE 13G/A
(12/31/2001)
OSI SYSTEMS INC
Cusip # 671044105
Amendment
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Cusip # 671044105
Item 1: REPORTING PERSONS
Dimensional Fund Advisors Inc. (Tax ID: 22-2370029)
Item 4: CITIZENSHIP
Delaware Corporation
Item 5: SOLE VOTING POWER
710800 ** see Note 1 **
Item 6: SHARED VOTING POWER --
None
Item 7: SOLE DISPOSITIVE POWER --
710800 ** see Note 1 **
Item 8: SHARED DISPOSITIVE POWER --
0
Item 9: AGGREGATE AMOUNT BENEFICIALLY OWNED --
710800 ** see Note 1 **
Item 11: PERCENT OF CLASS REPRESENTED BY LINE 9 --
5.715664201
Item 12: TYPE OF REPORTING PERSON --
IA
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ITEM 1(A). NAME OF ISSUER
OSI SYSTEMS INC
ITEM 1(B). ADDRESS OF ISSUER
12525 Chadron Ave
Hawthorne, CA 90250-4807
ITEM 2(A). NAME OF PERSON FILING
Dimensional Fund Advisors
ITEM 2(B). ADDRESS OF PRINCIPAL BUSINESS OFFICE
1299 Ocean Avenue, 11th Floor, Santa Monica, CA 90401
ITEM 2(C). CITIZENSHIP
A Delaware Corporation
ITEM 2(D). TITLE OF CLASS OF SECURITIES
Common Stock
ITEM 2(E). CUSIP NUMBER
671044105
ITEM 3. This statement is filed pursuant to Rule 13d-1 (b), or
13d-2 (b) and the person filing is an investment advisor
registered under section 203 of the Investment Advisors
Act of 1940.
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ITEM 4. OWNERSHIP
ITEM 4(a). AMOUNT BENEFICIALLY OWNED
710800 ** see Note 1 **
ITEM 4(b). PERCENT OF CLASS
5.715664201
ITEM 4(c). NUMBER OF SHARE AS TO WHICH SUCH PERSON HAS:
(i). SOLE POWER TO VOTE OR DIRECT THE VOTE --
710800 ** see Note 1 **
(ii). SHARED POWER TO VOTE OR TO DIRECT THE VOTE --
None
(iii). SOLE POWER TO DISPOSE OR TO DIRECT DISPOSITION OF --
710800 ** see Note 1 **
(iv). SHARE POWER TO DISPOSE OR TO DIRECT DISPOSISTION OF --
None
** Note 1 **
Dimensional Fund Advisors Inc. ("Dimensional"), an investment advisor
registered under Section 203 of the Investment Advisors Act of 1940,
furnishes investment advice to four investment companies registered
under the Investment Company Act of 1940, and serves as investment
manager to certain other commingled group trusts and separate accounts.
These investment companies, trusts and accounts are the "Funds". In its
role as investment advisor or manager, Dimensional possesses voting
and/or investment power over the securities of the Issuer described
in this schedule that are owned by the Funds. All securities reported
in this schedule are owned by the Funds. Dimensional disclaims beneficial
ownership of such securities.
ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS
If this statement is being filed to report the fact that
as of 12/31/2001 the reporting person has ceased to be the
beneficial owner of more than five percent of the class
of securities, check the following: []
ITEM 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF
ANOTHER PERSON
All Securities reported in this schedule are owned by
advisory clients of Dimensional Fund Advisors Inc., no one
of which to the knowledge of Dimensional Fund Advisors Inc.
owns more than 5% of the class. Dimensional Fund Advisors
Inc disclaims beneficial ownership of all such securities.
ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH
ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING
COMPANY:
Not Applicable
ITEM 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP
Not Applicable
ITEM 9. NOTICE OF DISSOLUTION OF GROUP
Not Applicable
ITEM 10. CERTIFICATION
By signing below I certify that, to the best of my knowledge
and belief, the securities referred to above were acquired
in the ordinary course of business and were not acquired for
the purpose of and do not have the effect of changing or
influencing the control of the issuer of such securities
and were not acquired in connection with or as a participant
in any transaction having such purposes or effect.
After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true,
complete are correct.
Signature
Wednesday, January 30, 2002
Michael T. Scardina
Vice President and Chief Financial Officer