how can I send a param to maintain some checkboxes - ruby-on-rails

Question

There were some similar topics and I tried them but I couldn't resolve.
code
<td><%= check_box_tag "words_info[]",word.id,false,{id:id} %><label for="<%=id%>" >追加</label></td>
The above code is called by below one which is a search form.
<h2>フラッシュカードを作成してください</h2><br>
<div class="col-md-12">
<h4>検索</h4>
<%= search_form_for #q,url:start_words_path do |f| %>
<%= f.label :title_cont, 'タイトル' %>
<%= f.text_field :title_cont %>
<%= f.label :user_name_cont,"作者"%>
<%= f.text_field :user_name_cont%>
<%= f.label :answer_cont,"答え"%>
<%= f.text_field :answer_cont%>
<%= f.label :question_cont,"問題"%>
<%= f.text_field :question_cont%>
<%= button_tag :type => "submit", :class =>"btn btn-send" do %>
<i class="material-icons left">search</i>検索
<% end %>
<%end%>
<%= form_tag({:action=>"practice"}, {:method=>"get"}) do %>
<%=render "words/words_index"%> #rendered here
<hr>
<%= submit_tag "完了" , class:"btn btn-large btn-send"%>
<% end%>
</div>
Everything that I tried
<td><%= check_box_tag "words_info[]",word.id,params[:words_info]==word.id,{id:id} %><label for="<%=id%>" >追加</label></td>
<td><%= check_box_tag "words_info[]",word.id,params[:words_info].include?(word.id),{id:id} %><label for="<%=id%>" >追加</label></td>
<td><%= check_box_tag "words_info[]",word.id,params[:words_info].to_s==word.id.to_s,{id:id} %><label for="<%=id%>" >追加</label></td>
environment
ruby 2.3
rails 4.2.7
materialize css