(redirected from control group)
Also found in: Dictionary, Thesaurus, Medical, Legal, Encyclopedia, Wikipedia.
Related to control group: independent variable


  1. a collection of people who interact with each other, are aware of each other and see themselves as a group. Very small groups, where each member knows the others well and can interact in a face-to-face manner, are often termed primary groups. Those with a larger membership where individuals are unable to interact directly with all the members are called secondary groups. Much of the work conducted in ORGANIZATIONS is done by groups. Work groups may take the form of either a number of people undertaking a particular task, directed by a manager (see MANAGEMENT) or SUPERVISOR, or a team in which coordination of a range of activities takes place and where status is more equal. The distinction is not a hard and fast one, but groups of production workers are generally referred to as ‘work groups’ whilst groups of managers tend to be referred to as teams. Both are formal groups in that they are consciously established to chieve certain work goals. By contrast, informal groups are those which emerge naturally, are based primarily on friendship, shared attributes or status, and whose membership does not necessarily coincide with that of formal groups. An early indication of the importance of social groups in organizations was provided by the HAWTHORNE STUDIES and exemplified in HUMAN RELATIONS philosophy The Hawthorne researchers found that informal groups could emerge alongside formal groups, with work norms which contradicted those of management. An earlier investigation in the research programme, however, seemed to find that a style of management (see MANAGEMENT STYLE, LEADERSHIP) which displayed an interest in workers could help collections of workers to cohere into effective groups, committed to managerial goals.

    Subsequently managers have adopted a variety of means to influence the activities of groups so as to harness them in support of managerial goals. One such measure is basing pay or bonuses on group output, so as to provide a stimulus to group members to work effectively together and to pressurize recalcitrant members into following group policy. Similarly, the creation of ‘semiautonomous work groups’ (see JOB DESIGN AND REDESIGN) with the power to allocate group members' tasks is designed to heighten both group cohesion and commitment to effective task performance. However, a question that still nevertheless vexes managers is why some groups are effective whilst others are not. For this reason substantial research has been conducted into group development and dynamics (i.e. the stages of growth that they go through and the patterns of interaction within them). One approach has suggested that groups go through four stages of development:

    1. forming (i.e. getting to know each other);
    2. storming (initial conflict as individuals compete for leadership positions and to influence the direction taken by the group);
    3. norming (the establishment of shared values);
    4. performing (where the group utilizes its strengths to perform desired activities). Many groups find difficulty in moving beyond the second and third stages. Team-building exercises, to encourage group cohesion, are an attempt to solve such problems. Research has shown that individual contributions to groups differ, and that in some cases they are effective whilst in others they are not. Management writer Meredith Belbin (1926-) has argued that each individual has a preferred team role and a secondary role which he or she adopts if unable to occupy his or her preferred role. These roles are chairman (setting the agenda), shaper (defining the task), plant (generating ideas), monitor/evaluator (evaluating ideas), company worker (organizing the group), resource investigator (seeking out resources), team worker (maintaining group cohesion) and finisher (ensuring deadlines are kept). On the basis of research of this type managers have attempted to influence group performance by selecting appropriate team members.

    Whilst team working is generally thought to be a useful approach to achieving organizational goals, it can have negative effects. The most damaging of these is groupthink, where pressures towards group conformity stifle creativity. See TEAM BREIFING.

  2. a collection of interrelated JOINT-STOCK COMPANIES which usually consists of a HOLDING COMPANY and a number of SUBSIDIARY COMPANIES and ASSOCIATED COMPANIES which tends to operate as a single business unit.
References in periodicals archive ?
The control group received two thank you text messages per month.
The patients included in the study were randomized into two groups--30 patients in the study (Cases) group were thrombolysed with 7.5 lakh units of streptokinase (half dose) over thirty minutes while the rest 30 patients in the control group were administered 1.5 million units of streptokinase (Conventional full dose) over one hour.
Kafali et al.24 conducted a study with 150 women in order to evaluate the effect of chewing gum after cesarean section on postoperative bowel activity and bowel sounds were significantly shorter in the study group (mean 5.9 hours) than in the control group (mean 6.7 hours) (p<0.01).
The average load of pulling was 1.03 [+ or -] 0.44 N for the WT control group and 18.49 [+ or -] 0.71 N for the knockout (KO) control group.
Primary outcome data were obtained for 218 and 216 participants in the intervention and control groups, respectively.
53 patients in control group were randomly assigned to receive conventional radiotherapy and 58 patients in study group to receive hypofractionated radiotherapy.
In intervention group, 20(60.0%) patients requested rescue analgesic compared to 30(87.5%) in the control group (p=0.013).
TN-C levels (Human TN-C) in the blood and aqueous humor (anterior chamber fluid) of PEX patients and control group were studied with the ELISA method (catalog number 201-12-1415 Sunred Biological Technology Co., Ltd., Shanghai, China) in accordance with the operating procedures specified in the kit instructions.
Analysis and interpretation of the results of the anthropometric development in the experimental group and in the control group
Methods: Twenty-four mice were randomly allocated to normal control group (n = 6), blank control group (n = 6), VEGF gene transfection group (n = 6), and NGF gene transfection group (n = 6).
Healthy calves whose clinical examinations proved no pathological findings and haematological data were normal, therefore formed the Control group (Group C; n = 20).