NATIONAL LABOR RELATIONS BOARD

160 THIRD ANNUAL REPORT OF NATIONAL LABOR RELATIONS BOARD
geographical basis. After finding that they should not be so divided,
the Board said :
With respect to the classes of employees to be excluded from the unit here
considered, the record discloses little more than the preferences of the rival
unions. As above stated, both unions agree on the exclusion of supervisory
employees. The International also claims that clerical workers, chemists, and
technical engineers should be excluded. No reason appears why these persons
should be included in the unit under consideration. We have heretofore held
that because of their special interests, clerical employees, engineers, and chemists
are prima facie unsuitable for inclusion in a unit with production employees.
We shall accordingly exclude clerical workers, chemists, and technical engineers,
as well as supervisory employees.
The Board has held in two eases that it would not entertain a
petition to change the appropriate unit found by the Board in a
decision, where the petition represents a change of position on the
part of the labor organization filing it, after losing an election conducted
on the basis of the former position. In Matter of Combustion
Engineering Company, Inc.," the Board directed the holding of an
election among employees of a particular craft. After the election,
the labor organization claiming to represent that craft filed a petition,
contending that the employees in i question should have been voted in
three separate groups. The Board stated :
The determination of the appropriate unit herein unquestionably followed the
desires of the Brotherhood as indicated in the record of this proceeding. The
Brotherhood's petition protesting this determination represents a change of
position clearly without merit.°
2. THE HISTORY AND PRESENT FORM OF SULF-ORGANIZATION AS FACTORS IN
DETERMINING THE APPROPRIATE UNIT
The form which self-organization has taken among the employers
involved in a proceeding, or among workers similarly situated, is
one of the most significant factors in i determining the appropriate
unit. Self-organization which has resulted in successful collective
bargaining in the past can be relied on as a guide for future collec-
Live bargaining. Similarly, the. form of self-organization presently
existing, and the rules governing eligibility to membership in the
labor organizations which have engaged in organization in the field,
aid in determining the most effective method of collective bargaining.
In taking these factors into consideration the Board utilizes
the experienced judgment of the workers themselv es as to the existence
of the mutual interest in working conditions which must exist
among the members of an appropriate unit.
(A) HISTORY OF LABOR RELATIONS IN THE INDUSTRY, AND BETWEEN THE
EMPLOYER AND HIS EMPLOYEES
The recognition through an established course of dealing between
an employer and his employees that a certain group of employees
should be treated together for the purposes of collective bargaining
is an important consideration in the determination of the appropriate
unit. Collective bargaining is facilitated by adhering to the
a° Matter of Combustion Engineering • Company, Inc. and Steel Workers Organizing Committee,
for and in behalf of Amalgamated Association of Iron, Steel and Tin Workers of
North America, 5 N. L. R. B. 344. Order dismissing petitions, 7 N. L. R. B. 123.
1), See also : Matter of Atlantic Basin Iron Works and Industrial Union of Marine and
Shipbuilding Workers of America, Local No. 13, 5 N. L. R. B. 402. • Certification of Representatives,
6 N. L. R. B. 441.