Newbie: Different context and associations for one model

Hi I have models (User and Meeting) like this:

== Schema Information

Table name: users

id :integer not null, primary key

name :string(255)

email :string(255)

created_at :datetime

updated_at :datetime

class User < ActiveRecord::Base
has_many :participations
has_many :meetings, :through => :participations
has_many :lectures, :class_name => “Meeting”
attr_accessible :name, :email

and:

== Schema Information

Table name: meetings

id :integer not null, primary key

starts_at :datetime

ends_at :datetime

title :string(255)

description :text

place :string(255)

tutor :string(255)

total_places :integer

google_event_id :string(255)

google_sync_status :string(255)

created_at :datetime

updated_at :datetime

class Meeting < ActiveRecord::Base

it allows tracking changes in models - see declaration of

validations
include ActiveModel::Dirty
has_many :participations
has_many :users, :through => :participations
belongs_to :tutor, :class_name => “User”, :foreign_key => “user_id”

and then I can find a tutor for a meeting but not the lectures for the
user. Should I make a migration containing:
add_column :meetings :references, :user_id (or tutor_id) ???
Will appreciate any suggestions
Cheers