I am a hypothetical dept. chairperson at a high school (I no longer get paid for the position but am still considered the chair). My authority is really next to nil but the dept members look to me for leadership issues. Our school district is pushing for PLCs (Professional Learning Communities which engage in common planning). We attempt to do this. However, one employee will sit in on common planning time and agree with everything being said, then returns to her classroom and does as she pleases without regard to the PLC plan. This has become very frustrating to most of us in the dept. but I have no actual authority to talk to her about this in a professional capacity. I have gone to my supervisor about other issues with this employee in the past and don't want it to seem as if I am "out to get her." How can I effectively handle the situation without appearing as if I have a personal vendetta against this particular employee?
If you have the leadership skills that are strong enough that others are willingly looking to you to lead things, I think you may have more influence than you give yourself credit for. The trick is, that it's influence but not authority. Although, I'll say, speaking as someone who's had both - that often authority is not all you think it is - often influence is the more powerful force.
Here's some things I'd try to see if you can stretch your influence enough to get the job done:
The goal with most of these is to get you out of the role of being the monitor for how this person performs her work. After all - that really is her supervisor's job. Your role, as the leader of the PLC Committee is to make sure that the new process of collaborative planning results in the desired outcome that different teachers produce the same good education for students. So all the suggestions above focus on you leading the team to a way of deciding what the outcome needs to be and then giving supervisors the tools to make sure that this outcome is part of the way they define "doing a good job".
When you are drafting your PLC plans, you need to be sure to include some sort of tangible device or metric which the members can use to measure the effectiveness of the plan. It may require a bit of creativity and imagination to implement this, but it serves multiple purposes. It allows you to identify whether or not parts of your plan are meeting the desired objectives, and, especially in the case of your "rogue", it easily identifies who is adhering to the plan. The metric itself does not have to be complicated or excessively detailed. It just needs to be enough to provide sufficient feedback so that non-participants can be easily pointed out and addressed.
If you don't have direct authority over this person I would think that issues regarding this person are a responsibility of her supervisor, not you.
Does this affect everyone, or is it a situation where the person's actions are not directly affecting others? If it affects other people in the team, I would arrange a meeting with the supervisor and include other team members so they can voice their concerns too. This would show that it isn't just you, not a personal vendetta, but rather a problem for the team.
You said you don't have any direct authority over others in the group and if this person is not taking the hint when issues are brought up with them then it becomes a problem for the manager/supervisor. Beyond that, there's not much you can do.
As for feeling like this person is being singled out that may happen no matter what to some degree. They're not playing nicely with the team so they're singling themselves out, and getting called out on it isn't so much being a target of a vendetta as it is not doing what they're supposed to be doing.
I also agreed with the previous answer mentioning metrics of some kind to measure progress and goals. If you're working in a more creative field, you may be loathe to use such tools, but it could prove important for record keeping and progress measurement, and may give a record to point out where the person is falling short. Just don't create a system of metrics that is based entirely on this person's actions; it should be broad enough in scope that it benefits the team, not curing a wayward member of the team.
Document everything and try not to become a defacto manager if they're not giving you the job title and pay raise to cover that kind of responsibility. :-)
Introducing change into any organisation is very hard, and takes time.
In this case, if I understand you correctly, you have a set of changes that have been agreed to in public, but you are facing non-compliance from an individual. This is a pretty typical passive/agressive type reaction; it tends to be more common with more introverted people, as extroverted people will usually let you know their objections (usually firing both barrels) in the meeting.
Either way, the person is letting you know that they feel stressed/angry about the process. This might be because they feel their views have not been heard or respected, that they haven't been consulted enough, that it threatens their status or they don't agree with it, or any one of a number of other "personal" trigger points.
I would suggest that you start off by observing the next meeting very carefully; you will probably need to find someone to observe and comment, especially if you always chair the meetings.
Look at how engaged people are in the process:
If you have people who are not fully engaged, then the meeting is to some extent, failing, as the primary goal is about cooperation and joint planning.
As chair, you can control a lot of how the meeting is organised. A few things I have found useful include:
All that said, if you have full engagement in the meeting and non-compliance then you need to step things up a notch.
You can hold a "stop and prop" meeting (a phrase from the coal-mining industy); go round the table asking everyone in turn to say "what is going well with the PLC process so far" first of all, and write these down on a white board. Give people an option to "pass" and go round the room until everyone has commented. Then go round the room asking "what could go better?" in the same pattern. This is a common approach to improvement in Agile software development, but can be highly effective in other areas too.
Finally, you may have to have a long one-on-one with the person in question; use open questioning and be non-judgemental, and try and explore what it is about the PLC process they dislike.
While I have used all of these approaches, they don't always work. As with all change, you can only move at the pace that the slowest person that you want to retain is prepared to move at.
I can understand the employee and sympathize with her. Having a joint curriculum decided upon by a committee of colleagues is counterproductive - teachers have widely varying qualifications and very often do not have the skills and knowledge to pick the best curriculum taking into account the frontier of science.
Design by committee can easily lead to dumbing down the curriculum to the level of the squeakiest wheel in the committee (pardon, PLC). If she is way smarter than the average member of the PLC, she may feel offended that the school district is trying (mindlessly) to undermine her work. She agrees to what you say in the meetings to weather out the storm of half-witted reforms being force-fed from above. At the very least, this is one interpretation of the story.
Am not a teacher though, and I take off my hat to the profession in general. In her shoes I either would have done the same or would have become a vocal opponent of the plan (if I believed my opposition could change anything).
The general conclusion relevant to Workplace SE would be: please pause for a minute and consider the possibility of her being right. If she's right, join her.
You need to notify this person and everyone else that the policy requires you to document non-compliance. This may become part of the teacher's permanent record.
Identify who is in authority and put the information in her hands. You may not be able to discipline this teacher, but you may be able to have her removed from your team.