Multi-layered table

Question

I'm a bit stuck at the moment. I want a table like the following (quickly drawn in Word, and I don't want the vertical lines as displayed - I'm using booktabs). The reason I'm making such a table is to summarise the findings of the literature review, and I'm splitting the studies by category (e.g. colour or music). Also, I'd like the column widths of the 'citation' column to be ever slightly bigger than the 'sample' and 'environment' columns, but smaller than the 'conclusion' column, which should be the biggest Please note that the white text and black background is not the colour scheme I want. I'm not sure about the colour options in Latex, but a background colour that would work well with black text would be fine - perhaps a light gray?

I began writing something in latex (so it is not a MWE) but I simply got stuck. I've included the packages of xcolor, because my googling revealed this how to fill in rows & columns, and I'm certain that my final table will span more than one page. Also would it be better if lines (of the same thickness) were between the "Colour" and "Music" 'sub-headings' ? Probably not.

\documentclass{article}
\usepackage{booktabs, xcolor, longtable}
\begin{document}
\begin{longtable}
\toprule
Citation & Sample & Environment & Conclusion
...
...
\end{longtable}
\end{document}

Answer 1

Displaying things like this may not be the good idea, but how to do it with LaTeX has answers.

\documentclass{article}
\usepackage{booktabs, longtable,array}
\usepackage[table]{xcolor}
\newcolumntype{P}[1]{>{\raggedright\arraybackslash}p{#1}}
\usepackage[a4paper,margin=1in]{geometry}
\begin{document}
\begin{longtable}{P{\dimexpr0.26\textwidth-2\tabcolsep-2\arrayrulewidth\relax}
                        P{\dimexpr0.18\textwidth-2\tabcolsep-\arrayrulewidth\relax}
                        P{\dimexpr0.19\textwidth-2\tabcolsep-\arrayrulewidth\relax}
                        P{\dimexpr0.37\textwidth-2\tabcolsep-\arrayrulewidth\relax}}
\toprule
Citation & Sample & Environment & Conclusion\\\midrule
\rowcolor{gray!20}\multicolumn{4}{c}{Colour}\\
Some name and some year in parenthesis & 300 adults & Furniture store & This is some long text that doen't really conclude in a single line\\\midrule
\rowcolor{gray!20}\multicolumn{4}{c}{Music}\\
Some name and some year in parenthesis & 300 adults & Furniture store & This is some long text that doen't really conclude in a single line\\
\bottomrule
\end{longtable}
\end{document}

Answer 2

An answer not as a table, as requested. You might want to use a enumerate or some other type of list, as the bullets probably look a bit bossy. I'd probably suppress the numbers on the subheadings too, but do whatever fits into your overall document design. I would also use \cite commands rather than writing out the references by hand if I were doing this for real.

\documentclass{article}
\begin{document}
\subsection{Summary of references}

[Explain the standard layout of each summarized reference.]

\subsubsection{References about colour}

\begin{itemize}
    \item Bellizzi, et. al. (1983) -- 125 adults -- furniture store

    Warm and cool colours created different emotional responses.  
    Customers view red detail environments as more negative and less pleasant
    than blue.

\item Smith and Jones (1977) -- 103 dogs -- pet shop

    A service-oriented paradigm is further compounded when taking into account the
    evolution of specifications over a given time period.  

\end{itemize}

\subsubsection{References about music}

\begin{itemize}

    \item Some name (1902) -- 300 adults -- Furniture store

    This is some long text that doesn't really conclude in a single line, and so we
    set it as a paragraph below.

\item And so on

\end{itemize}

\end{document}

General principle. You have several short things and one long thing for each item that you want to tabulate: if you set them in a table structure you inevitably waste a lot of space on the page. Setting them as structured paragraphs is (in my opinion) a bit easier on the reader.

<sarcasm> On the other hand if you want to bulk out your report, then a table with lots of blank space is a great way to go. Management consultants make a good living out of doing this. </sarcasm>