ich versuche folgende Graphik nachzubasteln in Latex:

Ich habe folgenden Code dazu gebastelt:
\documentclass{article} \usepackage{tikz} \usepackage{amsmath} \begin{document} \begin{tikzpicture}[ node distance=1.5cm and 2.5cm, every node/.style={draw, rectangle, align=center, rounded corners}, pre/.style={->,>=stealth',thick,draw=black!50}, post/.style={->,>=stealth',thick,draw=black!50} ] \node (research) [text width=4cm, fill=white] {Research design}; \node (traditional) [below left=of research, text width=3cm, fill=blue!20] {Traditional class}; \node (flipped) [below right=of research, text width=3cm, fill=blue!20] {Flipped class}; \node (pretest) [below=of research, text width=5cm, fill=white] {Pre-test algebra proficiency\\ Pre-test self-efficacy}; \node (training) [right=of flipped, xshift=-1cm, text width=3cm, fill=white] {Training sessions on the flipped approach}; \node (traditional_lessons) [below=of traditional, text width=3cm, fill=blue!20] {Traditional lessons}; \node (flipped_lessons) [below=of flipped, text width=3cm, fill=blue!20] {Flipped lessons}; \node (survey) [right=of flipped_lessons, xshift=-1cm, text width=3cm, fill=white] {Post-treatment survey}; \node (posttest) [below=of pretest, text width=5cm, fill=white] {Post-test algebra proficiency\\ Post-test self-efficacy}; \node (interview) [below=of posttest, text width=4cm, fill=white] {Teacher interview}; % Arrows \draw[pre] (research) -- (traditional); \draw[pre] (research) -- (flipped); \draw[pre] (traditional) -- (pretest); \draw[pre] (flipped) -- (pretest); \draw[pre] (flipped) -- (training); \draw[pre] (training) -- ++(0, -2) -| (pretest); \draw[pre] (pretest) -- (traditional_lessons); \draw[pre] (pretest) -- (flipped_lessons); \draw[post] (flipped_lessons) -- (survey); \draw[pre] (traditional_lessons) -- (posttest); \draw[pre] (flipped_lessons) -- (posttest); \draw[pre] (posttest) -- (interview); % Text Annotations \node at ($(pretest) + (-4, 0)$) {Weeks 1 + 2}; \node at ($(traditional_lessons) + (-4, 0)$) {Weeks 3 to 8}; \node at ($(posttest) + (4, 0)$) {Week 9}; \end{tikzpicture} \end{document}
VG & Danke
AP