LAWSM97.119

Teacher learning and the teaching of teachers

 

Michael Lawson

Robert Hattam

Peter McInerney

John Smyth

 

Flinders Institute for the Study of Teaching

Flinders University

Adelaide, South Australia

 

November 1997

 

Learning for change

Schools are necessarily caught up in social change. Recently the

demands on schools to change have increased and in some quarters much

is said about the need to bring about urgent 'reform' of public

education, so that schools can develop procedures and practices that

will enable graduates to respond effectively to the challenges

presented by social and economic change. As the Australian nation is

moved by government into the mainstream of the global economy and as

schools are moved by governments into the competitive market, students

and their teachers are being called upon to develop new perspectives

and practices that will allow them to thrive in these rapidly changing

conditions.

 

Some pressure for reform is perhaps a permanent feature of education,

since education involves growth. It is not so much the pressure for

reform that is noteworthy from time to time, but the urgency of the

call and its manifestations. In the US, there have been regular calls

for urgent reform of schools over the past four decades, where the

urgency is sometimes hidden in the title of the report of the task

force, such as in A Nation at Risk! There is currently a further

movement for reform of American schools (Lieberman, 1995).

 

In Australia our task forces have been fewer in number and the report

titles have been less evocative. But the pressures on schools to work

at helping to solve wider social problems has been increasing steadily

across the same period. The rise of a new social problem is often

associated with a call that "schools should do something about it", so

that a claim comes to be made on curriculum space that will help to

reduce the impact of the emerging problem. Literacy and vocational

training(VET) provide examples of areas where urgent responses are

currently being called for. Although literacy has been a popular

problem for schools across recent decades it has recently become an

urgent problem as the results of large scale testing have given it new

prominence. For the Federal minister responsible for schools there is

a need to reform the methods of teaching, to move away from what were

perceived to be unsuccessful, 'new fangled' methods. This solution,

and the analysis upon which it depends, seems deliberately simplistic

(see Luke, 1997)

 

Unemployment has been constructed by some quite powerful groups, like

the federal government, as a problem that can, at least in part, be

addressed by making a claim on curriculum space. This construction of

the problem is likely to prove fallacious, as the availability of paid

employment continues to decrease, so that the actions of schools, even

if they had maximal effect, can only be expected to have a weak impact

on the scale of the problem. Even so, schools are called upon to mount

an urgent response and, because they are in a competitive market,

non-response is dangerous. VET is once more in the vocabulary of

secondary school teachers because explicit vocational training in

schools is seen as an effective way to address the unemployment

problem.

 

The reality of literacy and employment problems is not being called

into question here. While these are good examples of the current

'urgent' problems with which schools are being confronted by

governments, they are real problems. They are, however, only the more

spectacular of the problems that continually face teachers and

educational systems. There are always less spectacular, though no less

important, problems for teachers to address, such as how to assist

students to be successful learners and responsible citizens. What is

of interest here is how governments, educational systems and

schools/teachers understand the processes that might engender change in

response to these problems.

 

Change from the top

The patterns of interaction of these three bodies - government,

educational system and teachers - in bringing about change presents an

interesting problem for analysis. One pattern, popular with

governments, is that governments set broad policy directions and seek

to have systems and schools respond in orienting themselves to these

directions. The means employed by governments to speed up the change

process are usually not subtle. The crudest response of government is

to mandate change. Analysis of this top down pattern of change

generation in the US suggests that it is sometimes less successful than

government policy makers might like to believe. The work done by

McLauglin(1987) on policy implementation in the US suggested that

mandated change does not always occur. Fullan (1994) has also argued

that such mandates have an unimpressive record in bringing about school

improvement. In an earlier discussion of change forces Fullan (1993:

138) described the pursuit of planned change as "a mug's game'

 

A slightly more subtle approach involves use of the funds attractor

mechanism. In Australia the federal government uses targeted funds to

engender change in both the state systems that are responsible for

educational provision and in schools. The federal government seems to

have a permanent pool of funds for this purpose. Every so often they

change the target and the title on the top of the application forms! .

Educational systems must respond to this by attempting to attract a

portion of these funds and so must engage directly with the government

reform agendas. In recent years the Key Competencies project has

provided an example where a federal policy initiative has directed

energy and activity in state systems through use of the funds

attractor. At least in South Australia we see the beginnings of an

impact on schools of this initiative being manifested in plans for 1998

(Department of Education and Children's Services, 1997).

 

Change from within

There is, of course, an alternative source of change within a school, a

source of change that is crucial for the health of the education

system. Indeed in other reports on this Teacher Learning Project (TLP)

in this symposium we have shown how schools have developed creative and

effective ways of responding creatively to external mandates by

appropriating the reform agenda in ways that are compatible with their

own educational agendas. However, the potential for bringing about

widespread change in a large number of schools is severely limited if

it restricted to use of these externally imposed mandates and fund

attractors. On their own, these attractors do not seem to have the

same power to induce the exponential change attributed to the "strange

attractors" of chaos theory. As McLauglin (1987) argues any of these

top down initiatives depend on 'local capacity' and 'local will', and

on the acceptance at the local level of the message at the centre of

the initiative. Other powerful change generators are available and

many of these reside within the school. The challenge for schools, and

for educational systems, is to recognise and understand the nature of

school-based change generators and to work out how these can be

supported and maintained.

 

In the wider Teachers' Learning Project we have attempted to identify

the nature of some of these local change generators that enable schools

to change and "move on" to develop more collaborative and critical

responses to their situations in order to improve the quality of

student learning. In previous papers in this symposium we have

described the part played by development of a coherent vision for the

school, by educative and distributed leadership, by data gathering, by

involvement with the community and by the creation of discussion spaces

for working on issues and tensions. The impact of these in the schools

involved in the project has been described in larger reports on the

case studies. These reports attest to the reform that has taken place

within the schools and document how this change has been facilitated by

the procedures developed by teachers and administrators. Here is a (if

not the) major set of change generators for an educational system, the

internally developed procedures and practices that will enable schools

to move on toward more powerful education for students.

 

How do teachers change their understanding of their teaching

situations? In this report we focus attention on what Fullan (1993)

refers to as a core capacity for change - the specific learning actions

and dispositions of teachers involved in generating change. Because we

accept that it is teachers and school leaders who provide the local

capacity and local will that drive change we argue that it necessary to

consider both the nature of learning being undertaken by these groups

and the ways in which this learning is facilitated by schools and

systems. For some it is surprising that the learning of teachers, and

the teaching of teachers, should be the object of study. Yet it is

teachers and leaders who shoulder the responsibility for student

learning. Just as we seek to understand and improve the learning and

teaching of students it is important to understand and improve the

learning and teaching of those who accept responsibility for students.

Examination of these specific processes, and of how they are supported

within a school, indicates that there is a need for schools , systems

and outside experts concerned with professional development to

re-evaluate the importance of informal teacher learning.

 

 

Teacher learning activities

Teachers learn quite a lot during the course of their teaching and it

is important to understand where and how this learning is occurring, to

consider the sites and formats of that learning. To illustrate this we

will draw on observations made in a case study of one of our project

schools where senior secondary teachers were heavily involved in

distance education of Year 11 and 12 students in a whole range of

different locations, from home to jail.

 

Table 1. Activities involving teacher learning

 

 

Locus of direction

 

Process

 

Type of activity

 

 

 

 

Professional reading

 

 

 

Reading of research

 

 

Reading/reflection

Reading of policy

 

 

 

Reflection

 

 

 

 

 

Individual

Observation

Observation

 

 

 

Visiting

 

 

 

 

 

 

 

Planning

 

 

Solo action

Teaching

 

 

 

Practice

 

 

 

 

 

 

 

 

 

 

Team teaching

 

 

 

Role playing

 

 

Participation

Joint planning

 

 

 

'Show me now'

 

 

 

Action research

 

 

 

Modelling

 

Collegial

 

 

 

 

 

Networking

 

 

 

Performance management

 

 

Conversation

Mentoring

 

 

 

Committee work

 

 

 

Learning teams

 

 

 

 

 

 

 

 

Lectures

 

'Experts'

Listening

Demonstrations

 

 

 

Formal study

 

 

 

 

 

 

 

This school was included in the project because use of the distance

education mode required significant learning on the part of teachers.

When teaching at this school both experienced teachers and novices had

to learn new sets of administrative procedures, new ways of teaching

and relating to students who were in a 'virtual' classroom, ways of

teaching in a space that was almost always inhabited by four or five

other teachers, and ways of teaching in a mode which resulted in

significant intensification of their work.

 

Our observations of teaching and discussions with teachers in this

school identified a range of the different activities that were sites

for teacher learning. We have listed these in the

right hand column of Table 1. The quite long list in that column

indicates the variety of opportunities there are for teacher learning

within this school. As is indicated in the other columns of Table 1

these activities can be differentiated on the basis of the processes

involved in the activity and the source of direction for the activity.

Some are generated and directed by the individual teacher, some through

collegial activity, while other activities are directed by other

people, quite commonly outside experts. Our focus here is, however on

the recognition of these activities as instances of teacher learning.

 

 

Formal and informal learning

Many of the activities listed in Table 1 are carried out as part of the

formal training and development activities of the school. These are

resourced and delivered through formally scheduled induction sessions,

school closure days, staff meetings, committee work, performance

management activity, and reports generated by working parties and the

leadership team. These activities explicitly provide spaces and

structures for key components of the learning that teachers need to

undertake in order to operate effectively in their teaching

environment. They are formally established and get onto the teachers'

learning agenda through the organisational structures of the school and

the education system. The activities cover a wide range of topics and

many are concerned with the details of the teaching/learning

interactions with students that occupy most of every teachers' working

day.

 

There is, however, a second category of these activities that are not

formally organised. These activities may also not be recognised as

instances of teacher learning and are typically not resourced in budget

planning. These informal teacher learning activities comprise the

larger grouping in Table 1. The individual activities, networking,

conversations, the "show me now" sessions, the observations and so on,

are different in character to the more formal learning activities.

These unstructured forms of learning are so closely woven into the

fabric of teachers' work and lives so as to appear almost invisible to

an outside observer, perhaps even to the teachers themselves.

 

In contrast to the formally organised Training and Development programs

described above, much of this informal learning is inseparable from the

daily routines and teaching practices that characterise the work of

teachers. This informal learning is different from much formal

learning in that:

It is focussed on ordinary events

It arises from, and is embedded in the everyday demands of teachers'

lives. It may not be recognised as learning because it arises from and

mostly occurs on-the-job. One experienced teacher commented on the

change in her questioning techniques across time:

I suppose it's hard to answer how that happens. I think it's

evolutionary. I mean how I probably questioned students...I expect is

very different to what I do now and its hard to think, really think

back and answer objectively from that time.

 

 

 

It is often not recognised as learning

It's amazing how much we've got built in us that comes out when you're

faced with situations. I guess that you do the same in a classroom when

you come to think of it. If a student has special needs in a classroom,

you do deal with them differently, to modify their curriculum, you give

them simpler tasks or parts of tasks to do, you don't put them on to

the extension work...you just try and think ways.

 

It is a response to an immediate need

I set that up myself, got one of the computer people, had some time on

a Friday, and said, 'Sit down with me and take me through the steps'.

 

It is rapidly executed

In cases such as that just noted, the urgency of the need to learn what

is typically a new procedure distracts attention away from the fact

that learning is taking place.

 

A colleague, or non-expert, is the teacher

In much informal learning it is most likely that it will be a

colleague, or significant other, who does the teaching. This also

contributes to the ordinary status accorded to the learning for this is

not seen to be a special event being presented by an 'expert' outsider.

The teacher may well be a student and in this school, for both

teachers and for members of the leadership team, was often a colleague

who had previously occupied the position.

Everyone's writing letters of introduction and I thought, oh god, I've

got to learn letters of introduction, I've got to learn how to do this,

so I just asked somebody and after one day they sat down and showed me

how to set up just the basics and I say down and I did it and I got

frustrated and I'd say 'Oh, got stuck', that sort of thing and then

there was a lap top here and I took it home and my son, 'How do you do

this? How do you do that?' And when I had to do the application I

learnt a lot then, it was slow, but I learnt a lot.

 

There was this laptop here and I took it home and (asked) my son, 'How

do you do this ?' And when I had to do the application I learnt a lot

then, it was slow, but I learnt a lot'

 

It is initiated by the learner

In the excerpts quoted here we see in each instance that the initiator

of the learning is the teacher. The goal is the established by the

teacher and the teaching is initiated in order to achieve that goal.

 

It may be incidental learning

The important role of informal learning in the development of teachers'

expertise is reinforced by discussions of the way that such learning

often occurs within the context of other, formal Training and

Development events. One teacher noted that DECS conferences for

teachers were important, not only for what might emerge from the

official program, but for the opportunities they offered for informal

learning:

 

I really like going to conferences and getting some information,

hearing how other teachers have done things and then having the chance

to sit down ... and say, 'Well when this sort of thing happens, what

did you do?' I like learning that way because it's practical.

 

 

Why is this informal learning of interest?

We can identify five reasons why we should give more attention to this

informal learning. First the discussions with teachers in this

Teachers' learning Project indicates that it widespread. The

conversations of teachers are liberally interspersed with anecdotes

providing details of such learning. The frequency of talk of formal

learning activities is much lower. As with teachers, managers in this

school also reported relying to a considerable extent on their

predecessors for knowledge of what to do and how it might be done,

especially during the early part of their appointments. Formal

management training did not support this necessary learning..

 

A second reason for our concern with this learning is that its

ordinariness gives it a very low profile. We have argued above that it

results in the construction of knowledge by teachers that they are

often unaware of.

 

Further examination of this learning is also justified because the

activities that generate it appear to be ones that are preferred by

teachers as forms of professional development. In a recent survey of

teachers in Queensland (Queensland Board of Teacher Registration, 1997)

respondents were asked to rate a number of different forms of

professional development in terms of their value and desirability.

From the excerpt taken from the report included below, included in

Table 2, it can be seen that activities such as networking, visits, and

collaborative teaching and learning activities are rated highly on both

counts.

 

Table 2. Preferred forms of professional development activities.

 

Professional development formata

Value:

%

respondents with high ratings

Preference:

%

respondents with high ratings

 

Highest rankings

 

 

 

Networking/interacting with colleagues

82(top ranking)

43

 

Seminars/workshops

81

45 (top ranking

 

Short courses

72

38

 

Visits/travel/exchanges

72

41

 

School-based collaborative teaching/learning activities

64

30

 

 

 

 

 

Lowest rankings

 

 

 

Guest lectures/public addresses

39

22

 

 

 

Action research

34

14

 

Lectures

23

16

 

Colloquiums/forums/symposiums

22

16

 

Preparation of academic papers

17

9

 

 

 

 

 

Adapted from the professional development rating survey from Making

your professional development count,(Queensland Board of Teacher

Registration, 1997).

 

The fourth issue associated with informal teacher learning is about the

extent to which it are resourced within schools and school systems. In

Table 3 below the range of teachers learning activities observed at the

school have been differentiated on the basis of their likely resourcing

within a school's Training and Development budget. The allocation of

resources to teacher learning is usually, though not exclusively, for

what we have referred to as the formal Training and Development

activities organised within the school or by the school system and it

is these that are listed in the right hand column of the table. The

division in Table 3 suggests that although the Training and Development

resources of the school and DECS allocate resources of time and money

to a wide range of teacher learning activities there is also a

substantial group of activities that are less likely to be allocated

resources in planning of college and system budgets. Examination of

the activities listed in the informal learning category suggests that

most incur no direct financial cost. Clearly they do require

allocation of teachers' time and it is this resource that needs to be

considered if the important role of this informal learning is to be

given more appropriate recognition.

 

Table 3. Likely resourcing of formal and informal teacher learning.

 

 

Informally resourced

 

 

Formally resourced

 

Reading/reflection

Visiting of educational sites

 

Observation

Role playing

 

Teaching and team teaching

Mentoring

 

Planning and joint planning

Action research

 

Practice and 'play'

Performance management

 

 

 

Learning teams

Training and Development committees

 

Conversations

Induction programs

 

Networking

Lectures

 

Questioning

Staff meetings

 

'Show me now'

Conferences and workshops

 

Demonstrations

 

 

Formal study

 

 

 

 

 

 

 

Our final reason for proposing that more attention be given to the

details and support of informal teacher learning is that it has a high

potential to result in quite powerful learning. Power is used here in

the sense that Bruner (1996, p. 47) used it to refer to the 'generative

value' of the constructed knowledge. To make this point in a suitable

manner it is necessary consider briefly how we might conceptualise the

nature of the process of learning.

 

 

Student learning and teacher learning

How should we consider the processes of teacher learning? Here we will

do this in two stages. First we will establish a framework for

discussing teacher learning and will then use that framework to reflect

on features of teacher learning we have observed in a case study of a

school involved in the TLP. Then we will consider teacher teaching and

how the teaching of teachers that we have observed seems compatible

with the broad learning framework.

 

Teacher learning is learning. We see no good reason to propose or

support a fundamental division of learning processes based upon a

difference in age. In adopting this view we accept the arguments made

by Susan Carey (1985) that the differences in child and adult learning

are largely knowledge based, not based on fundamentally different

representational systems in children and adults. For this reason it

seems sensible to examine teacher learning and teaching using

frameworks developed for the analysis of other learners, in this case

student learners.

 

The American Psychological Association commissioned a summary statement

on learning (American Psychological Association, 1993) that proposed a

set of principles that were representative of the current state of

research on student learning. This statement describes learning as a

process that is:

¥ active and constructive;

¥ goal-seeking and meaning-generating;

¥ directed by learners according to their beliefs, affective states and

motivations;

¥ facilitated by collaboration;

¥ and influenced by context.

 

 

 

These principles are central to a range of contemporary views of

student learning, including the notion of self-regulated learning

(e.g., Winne, 1995). In these views the motivational expectations and

strategic actions of students in achievement of their goals are seen as

key causal influences on what is learned. The same set of influences

operates when teacher are the learners. When teachers are learning

about their students, about teaching procedures, about their colleagues

and schools, or about the communities in which their students live, the

quality of their learning will depend upon these same factors. It will

depend upon their purposes, their dispositional states, the strategy

nature of the activity they undertake and, of course, on the way that

the teaching environment is organised.

 

 

Teaching for teacher learning

If this is the view of the teacher as learner we can ask how supportive

of such learning are the environments in which teacher learning occurs

That it is important to pursue such a question is suggested by a number

of recent commentaries on professional development. Here we will refer

to two of these. Ann Lieberman (1995) questioned whether the

conditions being set up for American teachers when they are learners

are ones that the teachers would set up for their own students.

 

Most of the in service training or staff development that teachers are

now exposed to is of a formal nature. Unconnected to classroom life,

it is often a melange of abstract ideas that pays little attention to

the ongoing support of continuous learning and changed practices

 

 

The second comment comes from a teacher involved in a case study in the

TLP.

 

I think the problem here is we're so intent on talking about the best

learning theories when we talk about student learning, the need to

reinforce information, the need to practice and apply. When it comes

to teachers, teachers forget about all those learning principles and

just assume that teachers can do those things automatically...they'll

sit you in a group because you're new and they'll just throw all this

information to you: information you need now, information you need at

the end of the year, at various times, and you're supposed to retain

all this information and know all the procedures.

(Case study teacher)

 

What are the preferred alternatives to these ways of teaching teachers?

The implications of the model of self-regulated learning for teaching

have been explored recently by Paris and Ayres (1994) and this provides

a useful starting point for considering the types of conditions that

might be more conducive to self-regulated teacher learning. We have

amended Paris and Ayres list slightly but support the thrust of their

view that self-regulated learning is likely to be facilitated by

environments that:

¥ allow for an element of personal choice on the part of the learner;

¥ provide a level of challenge relevant to the particular learner, so

that some degree of risk-taking is involved and is encouraged;

¥ allow the learner to take control of the direction in developing

plans and setting goals for their own learning;

¥ provide for collaboration;

¥ providing time for practice;

¥ is focussed on the construction of meaning and strategies that have

relevance to the learner's situation;

¥ encourage evaluation and reflection;

¥ are rewarding for the learner, so that further learning is

encouraged.

 

The emphasis in this list is on the individual activity of the learner

 

 

and, while it includes collaborative action, it could give more

attention to the influence of the context within which learning occurs.

Following the work examining the effect on student learning of the

school's sense of community (e.g. Battistich, Salomon, Watson & Schaps,

1997) we think it important to add one further condition to the Paris

and Ayres collection:

¥ the teaching environment provides a sense of community for learners

 

Teaching for self-regulated teacher learning

With this set of conditions argued to be ones that foster

self-regulated learning in students it is interesting to consider the

extent to which the instances of teacher learning we have listed in

Table 1, both formal and informal, are likely to have these

characteristics of self-regulation when teachers are students.

All of the activities included in Table 1 might, in particular

instances, vary substantially in the extent to which they encourage

self-regulatory learning Thus, a colleague may or may not encourage

effective collaboration when acting as teacher and an outside expert

may or may not engage teachers in collaborative examination of

challenging and relevant tasks. However, it seems reasonable to argue

that the self-directed and collegial learning activities could be

expected to involve several self-regulatory characteristics in most

instances - learner choice of goals and plans, learner control,

relevance to the immediate situation of the learner, a degree of risk,

and some sense of community.

 

Many of the examples discussed in the case study investigation in this

school were seen by teachers to be of this character. For example, the

learning generated from the teachers' work rooms was reported to be

collaborative, designed to be meaningful to the teacher, responsive to

the goals of the teacher, and allowed for further development of skill

in this area. The unusual nature of these work rooms, unusual for a

secondary school because teaching occurred in the presence of other

teachers, did create a sense of community.

 

The challenge for those teaching in the more formal sessions, during

the induction program, staff meetings and particularly during sessions

run by outside experts, is to get close to the situations of the

individual teachers. In these cases it is more difficult to do this

than it is in the work rooms, because the individual teachers'

situations vary quite widely. Some of the formal sessions we observed

were mainly talk sessions in which quite a large amount of information

was presented at the one time. By way of contrast, the role playing

sessions in which worst and best practice were simulated by staff

provided examples of formal training and development sessions that were

directed by others but which had high potential to be self-regulatory

for individual participants. The challenge for those who are designing

these other-directed, more formal sessions is to seek to facilitate

some degree of self-regulation for the teachers who are acting as

learners.

 

 

Implications

Change can be generated from within a school. In other papers in this

symposium a set of practices and policies that generate productive

change have been described. The outcome of these practices is, to a

substantial extent, dependent on the changes in understandings held by

teachers about their teaching and about their communities. Powerful

changes in understanding are not only generated by formal professional

development. The analysis set out here, based on case studies of

schools engaged in a moving on process, indicates that change in

understanding is also generated by the teachers' informal learning

activities. The widespread nature of these activities, and their low

profile in the training and development agendas, suggests that they may

be undervalued and under-resourced. Unless they become more explicit

components of professional development plans and budgets their value as

generators of change may not be realised. Their self-regulatory

character suggests that they can also be used as a guide in the design

of the necessary formal professional development activities for

teachers.

 

 

References

 

American Psychological Association (1993) Learner-centred psychological

principles: Guidelines for school redesign and reform. Washington,

D.C: American Psychological Association.

 

Battistich, V., Solomon, D., Watson, M., & Schaps, E. (1997). Caring

school communities. Educational Psychologist, 32, 137 - 151.

 

Bruner, J. (1966). Toward a theory of instruction. New York: Norton.

 

Carey, S. (1985). Are children fundamentally different kinds of

thinkers and learners than adults? In S. Chipman, J. W. Segal & R.

Glaser, (Eds.). Thinking and learning skills (Vol. 2). Hillsdale, N.J:

Erlbaum.

 

Department of Education and Children's Services, (1997). Integrating

the Key competencies into teaching and learning practice. Adelaide.

 

Fullan, M. G. (1993) Change forces. London: Falmer Press.

 

Fullan, M.G. (1994) Coordinating top-down and bottom-up strategies for

educational reform. In R. Anson (Ed.). Systemic reform: Perspectives

on personalizing education (pp. 7 -23). Washington, D.C: US Department

of Educational Research and Improvement.

 

Lieberman, A. (1995). Practices that support teacher development. Phi

Delta Kappan, 76, 591 - 596.

 

Luke, A. (1997). New narratives of human capital: Recent redirections

in Australian educational policy. Australian Educational Researcher,

24, 1 - 21

 

McLaughlin, M. (1987). Learning from experience: lessons from policy

implementation. Educational Evaluation and Policy Analysis, 9, 171 -

178.

 

Paris, S. G. & Ayres, l. R. (1994) Becoming reflective students and

teachers. Washington, D.C: American Psychological Association.

 

Queensland Board of Teacher Registration, (1997).Making your

professional development count. Brisbane.

 

Winne, P. H. (1995). Inherent details in self-regulated learning.

Educational Psychologist, 30, 173 -187.

 

 

 

 

 

14

Teacher learning and the teaching of teachers