Enhancing the Effectiveness of
Work Groups and Teams
Steve W.J. Kozlowski and Daniel R. Ilgen
Michigan State University
SUMMARY—Teams of people working together for a com-
mon purpose have been a centerpiece of human social or-
ganization ever since our ancient ancestors first banded
together to hunt game, raise families, and defend their
communities. Human history is largely a story of people
working together in groups to explore, achieve, and con-
quer. Yet, the modern concept of work in large organiza-
tions that developed in the late 19th and early 20th
centuries is largely a tale of work as a collection of indi-
vidual jobs. A variety of global forces unfolding over the
last two decades, however, has pushed organizations
worldwide to restructure work around teams, to enable
more rapid, flexible, and adaptive responses to the unex-
pected. This shift in the structure of work has made team
effectiveness a salient organizational concern.
Teams touch our lives everyday and their effectiveness is
important to well-being across a wide range of societal
functions. There is over 50 years of psychological re-
search—literally thousands of studies—focused on
understanding and influencing the processes that underlie
team effectiveness. Our goal in this monograph is to sift
through this voluminous literature to identify what we
know, what we think we know, and what we need to know to
improve the effectiveness of work groups and teams.
We begin by defining team effectiveness and establishing
the concept ual underpinnings of our approach to under-
standing it. We then turn to our review, which concentrates
primarily on topics that have well-developed theoretical
and empirical foundations, to ensure that our conclusions
and recommendations are on firm footing. Our review
begins by focusing on cognitive, motivational/affective,
and behavioral team processes—processes that enable
team members to combine their resources to resolve task
demands and, in so doing, be effective. We then turn our
attention to identifying interventions, or ‘‘levers,’’ that can
shape or align team processes and thereby provide tools
and applications that can improve team effectiveness.
Topic-specific conclusions and recommendations are given
throughout the review. There is a solid foundation for
concluding that there is an emerging science of team ef-
fectiveness and that findings from this research foundation
provide several means to improve team effectiveness. In
the concluding section, we summarize our primary find-
ings to highlight specific research, application, and policy
recommendations for enhancing the effectiveness of work
groups and teams.
INTRODUCTION
‘‘Houston, we’ve had a problem.’’ Apollo 13 was more than
halfway on her journey to Earth’s moon on what was to have been
a routine mission to collect samples when, suddenly, the mission
and the lives of the crew were in grave jeopardy. One of the
spacecraft’s two oxygen tanks exploded, blowing out the entire
side of the service module and damaging the remaining oxygen
tank. Within 3 hours, all oxygen stores were depleted, and the
craft lost water, electrical power, and propulsion. The situation
was critical, time was short, and there was no margin for error.
A team of NASA engineers was hastily assembled. Their mission:
problem-solve, adapt, and invent a way for the crew to survive and
to pilot their damaged spacecraft back to Earth. The team was
successful, transforming a potentially disastrous mission into a
legend of effective teamwork (NASA Goddard Space Flight
Center, n.d.).
Jump to Nepal, deep in the heart of the Himalaya Mountains.
Several international teams were mounting that annual cam-
paign of human striving and accomplishment, attempting to
reach the summit of Mt. Everest—‘‘an intrinsically irrational
act’’ (Krakauer, 1997, p. xvii). The teams were led by renowned
mountaineers, but this season on Everest turned out to be the
most disastrous one of all time. On one team, of five teammates
who reached the peak, four, including the veteran leader, died.
Nine climbers from four other expeditions also perished. Before
the month was out, 16 climbers lost their lives attempting to
Address correspondence to Steve W.J. Kozlowski, Department of
Psychology, 309 Psychology Building, Michigan State University, East
Lansing, MI 48824-1116; e-mail: stevekoz@msu.edu.
PSYCHOLOGICAL SCIENCE IN THE PUBLIC INTEREST
Volume 7—Number 3 77Copyright r 2006 Association for Psychological Science
reach the treacherous summit. Although the harsh, unforgiving,
and constantly changing environment played a major role in this
tragedy, the perilous conditions were exacerbated by failures of
team leadership, coordination, and communication (Krakauer,
1997).
Teams of people working together for a common cause touch
all our lives. From everyday activities like air travel, fire fight-
ing, and running the United Way drive to amazing feats of human
accomplishment like climbing Mt. Everest and reaching for the
stars, teams are at the center of how work gets done in modern
life. Although how teams function is often beneath the level of
everyday awareness, unexpected successes, such as Team USA’s
winning of the Olympic Gold Medal for Hockey, and failures,
such as FEMA’s sluggish response to hurricane Katrina, make
team functioning and team effectiveness highly salient. Failures
of team leadership, coordination, and communication are well-
documented causes of the majority of air crashes, medical er-
rors, and industrial disasters. They have also been implicated in
many political and military catastrophes, including the mis-
calculated Bay of Pigs invasion, the mistaken downing of a ci-
vilian airliner by the USS Vincennes, the failure of the USS Stark
to take defensive action against a hostile missile attack, and the
failure to prevent the tragedy of 9/11. Our point is simple: teams
are central and vital to everything we do in modern life. Our
purpose in this monograph is to elucidate what more than 50 years
of research on small groups and teams can tell us about the
processes that contribute to team effectiveness and, based on that
knowledge, to identify leverage points that can be used to make
teams more effective.
Review Focus and Structure
Organizations around the world are well along a decade-and-a-
half evolution in the design of work—shifting from individual
jobs in functionalized structures to teams embedded in more
complex workflow systems (Devine, Clayton, Phillips, Dunford,
& Melner, 1999; Lawler, Mohrman, & Ledford, 1992, 1995;
Mathieu, Marks, & Zaccaro, 2001). A variety of forces are
driving this shift. Increasing competition, consolidation, and
innovation create pressures for skill diversity, high levels of
expertise, rapid response, and adaptability. Teams enable these
characteristics (Kozlowski, Gully, Nason, & Smith, 1999). The
increasing penetration of computers into all facets of the
workplace coupled with broadband communication allows
teams to be located together or distributed across time and space
(Bell & Kozlowski, 2002b). Multicultural teams linked across
the globe by technology are on the rise.
Concomitant with this shift in the organization of work is the
shift in research focus from the study of small interpersonal
groups in social psychology to the study of work teams in or-
ganizational psychology. This shift in the core of team research
was explicitly recognized by Moreland, Hogg, and Hains (1994),
who noted the relative decline of group research in social psy-
chology, and by Levine and Moreland (1990), who concluded
that small-group research ‘‘is alive and well and living elsewhere
[outside the confines of social-psychology laboratories]’’ (p.
620). At least seven major reviews of the work-team literature in
organizational psychology appeared between 1990 and 2000
(see Bettenhausen, 1991; Cohen & Bailey, 1997; Gully, 2000;
Guzzo & Dickson, 1996; Guzzo & Shea, 1992; Hackman, 1992;
Sundstrom, McIntyre, Halfhill, & Richards, 2000).
1
More recent
reviews of work-team research (Ilgen, Hollenbeck, Johnson, &
Jundt, 2005; Kozlowski & Bell, 2003) reflect the emerging
perspective of work teams as dynamic, emergent, and adaptive
entities embedded in a multilevel (individual, team, organiza-
tion) system (cf. Arrow, McGrath, & Berdahl, 2000; Kozlowski et
al., 1999; Marks, Mathieu, & Zaccaro, 2001). That is, teams are
complex dynamic systems that exist in a context, develop as
members interact over time, and evolve and adapt as situational
demands unfold.
Dynamic complexity; emergent team processes and phe-
nomena; and development, evolution, and adaptation are key
themes that will be reflected in our review. We will describe what
we mean in more detail in the next section, but a brief overview
here is useful because it sets the structure for our focus and
approach. As illustrated in Figure 1, a team is embedded in a
broader system context and task environment that drives team
task demands; that is, the task requirements necessary to resolve
the problem or situation presented by the environment and the
load placed on team members’ resources. A dynamic, shifting,
and complex environment creates commensurate team task
demands that members have to resolve though a coordinated
process that combines their cognitive, motivational/affective,
and behavioral resources. As Figure 1 shows, this process is
cyclical and reciprocal. When team processes are aligned with
environmentally driven task demands, the team is effective;
when they are not, the team is not. Our approach is guided by
this basic heuristic and the focal points of our review are cap-
tured in the highlighted portion of the figure. We first consider
team effectiveness as a dynamic process. We next review the
research base to identify critical team processes and emergent
states that contribute to team effectiveness. Having established
that research foundation, we then consider factors that can in-
fluence, shape, and create appropriate team processes. Thus,
our basic questions in this review are: What are the key team
processes and emergent states that influence team effectiveness?
How can these processes and states be leveraged to better create,
develop, and manage effective work teams?
1
Kerr and Tindale (2004) reviewed research on small-group performance and
decision making that, while taking a social-psychological focus, shows an in-
teresting overlap in some research topics that are more central to an organiza-
tional-psychology focus—especially theory and research on shared or collective
cognition as it relates to team performance and effectiveness. See also the review
in this journal by Mannix & Neale (2005) on team diversity, decision making, and
performance.
78 Volume 7—Number 3
Enhancing the Effectiveness of Work Groups and Teams
There has been well over a half century of research in both
social psychology and organizational psychology on small
groups and teams and related topics. Virtually all of the research
papers close with the obligatory acknowledgement that ‘‘more
research is needed.’’ And, while it is true that there is much we
psychologists do not yet know about team effectiveness, there is
much that we do. There is a substantial knowledge base. The real
challenge is sifting through this vast literature to isolate those
promising team processes that reliably influence team effec-
tiveness and that can also be shaped by deliberate intervention.
Our intent in this review is to focus on those key areas in which
theory and research findings are well developed and therefore
provide a solid substantive basis for actionable recommenda-
tions. Although this review is ultimately guided by our own
theoretical perspectives, empirical research, and professional
judgment, we relied on three primary strategies to identify key
areas. First, we sought research topics that were sufficiently
mature that they had been the target of one or more meta-ana-
lytic reviews.
2
Meta-analytic findings provide a quantitative
foundation for our most forceful conclusions and recommenda-
tions. Second, we sought topics that, though not meta-analyzed,
had been the subject of substantial systematic empirical re-
search. For these areas, our conclusions and recommendations
are strong but not unequivocal. Finally, we also considered areas
that reflect emerging theory and promising, though not yet ex-
tensive, research support. The potential of these areas is more a
matter of our judgment and the conclusions and recommenda-
tions are therefore intended to be more circumspect. As in any
such endeavor, our decisions about what to include and exclude
will not please everyone. We offer apologies in advance to all
whose work may have been overlooked.
We now begin by articulating our theoretical perspective, as it
highlights important themes of our review and its structure. We
next review research on team processes and emergent states,
giving recommendations about those that are actionable and
those that require further development and research attention.
We then shift to an identification of several potent intervention
‘‘levers’’ that can shape team processes. If you want to know how
to enhance team effectiveness, this is how it can be accom-
plished. The policy implications in these two core sections are
self-evident. Finally, we close with a summary of our many
recommendations and more general policy implications for the
enhancement of team effectiveness.
The Nature of Teams and Team Effectiveness
What Is a Team?
A team can be defined as (a) two or more individuals
3
who (b)
socially interact (face-to-face or, increasingly, virtually); (c)
possess one or more common goals; (d) are brought together to
perform organizationally relevant tasks; (e) exhibit interde-
pendencies with respect to workflow, goals, and outcomes; (f)
have different roles and responsibilities; and (g) are together
embedded in an encompassing organizational system, with
boundaries and linkages to the broader system context and task
environment (Alderfer, 1977; Argote & McGrath, 1993; Hack-
man, 1992; Hollenbeck et al., 1995; Kozlowski & Bell, 2003;
Kozlowski, Gully, McHugh, Salas, & Cannon-Bowers, 1996;
Kozlowski et al., 1999; Salas, Dickinson, Converse, & Tan-
nenbaum, 1992).
What Is Team Effectiv eness?
The conceptualization of team effectiveness that has shaped the
last 40 years of theory and research is based on the logic of an
input–process–output (I-P-O) heuristic formulated by McGrath
(1964; cf. Gladstein, 1984; Salas et al., 1992). In this framework,
inputs refer to the composition of the team in terms of the con-
stellation of individual characteristics and resources at multiple
levels (individual, team, organization). Processes refer to activ-
ities that team members engage in, combining their resources to
resolve (or fail to resolve) task demands. Processes thus mediate
the translation of inputs to outcomes. Although team processes
are by definition dynamic, they are most typically addressed in
static terms—as constructs that emerge over time (i.e., emergent
states) as team members interact and the team develops (Koz-
lowski et al., 1999; Marks et al., 2001). Output has three facets:
(a) performance judged by relevant others external to the team;
(b) meeting of team-member needs; and (c) viability, or the
willingness of members to remain in the team (Hackman, 1987).
Fig. 1. Conceptual framework and review focus. The figure illustrates
that environmental dynamics and complexity drive team task demands;
team processes and emergent states align team-member resources to re-
solve task demands and yield team effectiveness; and team outputs (ef-
fectiveness) reciprocally influence the environment, in an ongoing cycle.
The focus of this report is shaded: team processes and emergent states; and
the factors that shape, leverage, or align them.
2
Meta-analysis statistically combines the findings from many primary studies
that examine the same relationship to provide an estimate of the magnitude of the
relationship, correlation, or ‘‘effect size’’ in the population.
3
Some scholars distinguish dyads from teams made up of three or more people.
In our view, many two-person teams (e.g., aircrews) exhibit the same basic work
processes underlying team effectiveness as larger teams. However, we do ac-
knowledge that teams of three or more enable coalitions and related interper-
sonal interaction complexities that are absent in dyads.
Volume 7—Number 3 79
Steve W.J. Kozlowski and Daniel R. Ilgen
These tripartite facets capture the prevalent conceptualization
of team effectiveness. Although McGrath’s heuristic is a useful
organizing framework—it was developed to organize the re-
search literature on small groups circa 1964—it was not in-
tended to be a theory or a formal causal model of team
effectiveness. It has, nonetheless, been frequently interpreted as
a model to be tested. We think that while the I-P-O model is a
useful organizing heuristic, treating it as a causal model en-
courages taking a limited and static perspective on team ef-
fectiveness and the dynamic processes that underlie it.
A Dynamic View of Team Processes and Effectiveness
We adopt a more contemporary perspective that has evolved over
the last decade, which conceptualizes the team as embedded in a
multilevel system that has individual, team, and organizational-
level aspects; which focuses centrally on task-relevant processes;
which incorporates temporal dynamics encompassing episodic
tasks and developmental progression; and which views team
processes and effectiveness as emergent phenomena unfolding in a
proximal task- or social context that teams in part enact while also
being embedded in a larger organization system or environmental
context (Arrow et al., 2000; Ilgen et al., 2005; Kozlowski & Bell,
2003; Kozlowski et al., 1999; Kozlowski, Gully, McHugh et al.,
1996; Marks et al., 2001). We now briefly highlight the key themes
of this extension, elaboration, and refinement of the I-P-O heu-
ristic; these themes play an important role in our conceptualiza-
tion and organization of the literature and in our effort to make
actionable recommendations based on that literature.
Multilevel System Context
Individual team members comprise the team as a collective entity,
an entity that also serves as the social context that influences in-
dividual members (Hackman, 1992). Moreover, as illustrated in
Figure 1, team members and work teams are embedded in a
broader organizational system and task environment that drives
the difficulty, complexity, and tempo of the team task. The inter-
actions are reciprocal in that team performance outputs resolve
task demands emerging from the surrounding system or environ-
ment and change the state of the system or environment in some
fashion. These changes can shift unexpectedly and the team must
adapt to the changing demands. Thus, it is necessary to understand
the system context and linkages across multiple levels—individ-
ual, team, organization—as key sources of contingencies or de-
mands on the team that necessitate aligned team processes
(Kozlowski et al., 1999; Kozlowski, Gully, McHugh et al., 1996).
The degree to which teams are embedded in or tightly linked
to the organizational system or a dynamic task environment can
vary. Some teams or small units, while part of an organizational
system, are more tightly linked to a dynamic task environment
that is their dominant embedding context for task activity. As
an example, consider a surgical team in the operating room
(OR) where what is happening with the patient right now (e.g.,
dropping blood pressure, respiratory difficulty, erratic heart-
beat) defines the task environment, which then drives team task
demands and team-member activity. Relative to the broader
organizational-system context (e.g., new policies adopted by
hospital administration), the task environment is the primary
context in which the OR team is embedded. The situation is
similar for aircrews or firefighting teams, in which the task en-
vironment (i.e., take-offs, storms, and landings, or fire, fuel,
wind, and humidity, respectively) is the primary embedding
context. For other teams, the broader organizational system is
the primary context. A cross-functional project team making a
recommendation to management on product development or a
top-management team (TMT) revising organizational strategy to
meet stiff competition are more tightly included in the organ-
izational system as the primary embedding context.
The Team Task
The central focus on what teams have to do—their task—is the
key factor that distinguishes a social-psychological perspective
on the study of teams, in which the task is merely a means to
prompt interpersonal interaction, from an organizational per-
spective, in which the task is the source of goals, roles, and task-
based exchanges. For the latter, interpersonal interaction is
relevant, but it is in the background rather than the foreground.
The team task determines two critical issues. First, it sets
minimum requirements for the resource pool—the constellation
of team-member individual differences and capabilities—that
is available across team members. If members collectively lack
necessary knowledge, skills, abilities, or resources to resolve the
team task, the team cannot be effective. Second, the team task
determines the primary focus of team-member activities. Our
focus is on teams that primarily do things (e.g., action or pro-
duction teams) and that, in the process of striving toward and
accomplishing goals, also have to make decisions (e.g., project
teams or TMTs) and create, invent, and adapt solutions to resolve
task-driven problems.
4
Thus, the team task determines the workflow structure and
coordination demands (i.e., exchanges of behavior, information,
etc.) necessary for accomplishing individual and team goals and
resolving task requirements. Team processes as emergent con-
structs or ‘‘states’’ are a way to capture coordination of team-
member effort and factors relevant to it, as well as the alignment
of team processes with task demands. In that sense, appropri-
ately aligned team action processes are critical enablers of team
effectiveness (Kozlowski et al., 1999; Kozlowski, Gully, McHugh
et al., 1996; Marks et al., 2001; Salas et al., 1992).
4
Our primary focus is on action teams because it covers the broadest type of
teams relevant in organizations. Decision making and creativity are important
aspects of action but are not the unitary focus of activity. Readers interested in
the specific and extensive research in these areas are directed to Kerr and
Tindale (2004) for a recent review on group decision making. Similarly, we do not
specifically review the voluminous research on team composition and diversity.
Interested readers are directed to Mannix and Neale (2005) for a comprehensive
review.
80 Volume 7—Number 3
Enhancing the Effectiveness of Work Groups and Teams
Time
Team processes develop and unfold over time (McGrath, 1991).
The extent to which team processes align with task demands is a
function of team learning, skill acquisition, and development.
Key temporal dimensions include (a) task cycles or episodes that
‘‘entrain’’ the team to task dynamics by making specific, itera-
tive, and repeated demands on team processes (Ancona &
Chong, 1996; Kozlowski, Gully, McHugh et al., 1996; Marks et
al. 2001) and (b) linear development of indeterminate duration
across the team’s life cycle of formation, development, mainte-
nance, and decline/dissolution (Tuckman, 1965; Kozlowski et
al., 1999). The important points here are that team tasks are not
fixed—they vary in their demands on team processes—and that
team process capabilities are not fixed—they compile and im-
prove as team members accrue experiences and learn how to
work together better. And, although processes are clearly dy-
namic, over time stable process constructs, or what Marks et al.
(2001) call emergent states, develop, providing a means to cap-
ture or summarize team processes.
Our Approach
We begin our review by establishing what we know about critical
team processes and emergent states and how they contribute to
team effectiveness. Our purpose is to identify processes that
have well-established, research-based linkages to team effec-
tiveness that therefore should be targets for interventions to
improve team functioning. We then highlight research-based
interventions that can leverage team processes. With that
foundation, we provide recommendations for enhancing team
processes and effectiveness and offer suggestions for future
research and applications.
TEAM PROCESSES, EMERGENT STATES, AND
EFFECTIVENESS
Conceptually, process captures how team members combine
their individual resources, coordinating knowledge, skill, and
effort to resolve task demands. Team effectiveness (i.e., per-
formance evaluated by others, member satisfaction, viability) is
an emergent result that unfolds across levels (individual to dy-
adic to team) and over time. This perspective on team processes
is clearly dynamic, but it is also the case that the repeated in-
teractions among individuals that constitute processes tend to
regularize, such that shared structures and emergent states
crystallize and then serve to guide subsequent process inter-
actions. Process begets structure, which in turn guides process.
Allport (1954) described this reciprocal nature of process and
structure in terms of ‘‘ongoings,’’ Katz and Kahn (1966) in terms
of ‘‘role exchanges,’’ Kozlowski and Klein (2000) in terms of
‘‘emergent phenomena,’’ and Marks et al. (2001) in terms of
‘‘emergent states.’’ Thus it is important to appreciate that while
processes are dynamic and therefore difficult to capture in real
time, they yield collective cognitive structures, emergent states,
and regular behavior patterns that have been enacted by, but
also guide, team processes.
In that sense, team cognitive structures, emergent states, and
routinized behavior patterns are the echoes of repeated process
interactions (Kozlowski & Klein, 2000) and, hence, are indic-
ative of the nature and quality of dynamic team processes.
Following the structure set by Kozlowski and Bell (2003) and
Ilgen et al. (2005) in their previous reviews, we classify team
processes and their echoes according to whether they are cog-
nitive, affective/motivational, or behavioral in nature.
5
Team Cognitive Processes and Structures
Small-group research has a long tradition of studying cognitive
constructs such as group norms and role expectations that guide
interpersonal interactions among team members. While not
denying the importance of interpersonal interactions, research
in organizational psychology has tended to address cognitive
constructs that are more focused on guiding task-relevant in-
teractions among team members. Indeed, work groups and teams
have been characterized as processors of information (Hinsz,
Tindale, & Vollrath, 1997). We focus on a set of team cognitive
constructs that represent the structure of collective perception,
cognitive structure or knowledge organization, and knowledge or
information acquisition—constructs that have amassed a suffi-
cient research foundation to support their value for enhancing
team effectiveness. These collective constructs include unit and
team climate, team mental models and transactive memory, and
team learning.
Unit and Team Climate
The notion of climate as an interpretation of the group situation
or environment can be traced back to early work by Lewin,
Lippitt, and White (1939), with much research and development
over the intervening decades (see Forehand & Gilmer, 1964;
James & Jones, 1974; Ostroff, Kinicki, & Tamkins, 2003 for
comprehensive reviews). Contemporary theory and research
regard climate as cognitively based, descriptive, interpretive
perceptions of salient features, events, and processes (James &
Jones, 1974) that characterize the ‘‘strategic imperatives’’
(Schneider, Wheeler, & Cox, 1992) of the organizational and
team context. Although such perceptions originate within the
person, exposure to strong strategic imperatives or situations
(Gonza
´
lez-Roma
´
, Peiro
´
, & Tordera, 2002); perceptual filtering
and interpretation by leaders (Kozlowski & Doherty, 1989); and
social interaction, sharing of perspectives, and collective sense
making (Rentsch, 1990) can shape a convergent emergent
5
Any effort to classify team processes into the cognitive, motivational/af-
fective, and behavioral categories we adopted will have some topics that could
potentially fit in an alternate category. The classification simply reflects our
judgment of best fit. Moreover, as we indicated in the introduction, our selection
of topics was driven by the sufficiency of theory and the research base to provide
a basis for recommendations. We make no claim of exhaustive coverage of every
possible topic or investigation.
Volume 7—Number 3 81
Steve W.J. Kozlowski and Daniel R. Ilgen
