diff --git a/bootstrap/exercises/Makefile b/bootstrap/exercises/Makefile
new file mode 100644
index 0000000..27691d9
--- /dev/null
+++ b/bootstrap/exercises/Makefile
@@ -0,0 +1,34 @@
+TEXFILES=$(wildcard exercises??.tex)
+EXERCISES=$(TEXFILES:.tex=.pdf)
+SOLUTIONS=$(EXERCISES:exercises%=solutions%)
+
+.PHONY: pdf exercises solutions watch watchexercises watchsolutions clean
+
+pdf : $(SOLUTIONS) $(EXERCISES)
+
+exercises : $(EXERCISES)
+
+solutions : $(SOLUTIONS)
+
+$(SOLUTIONS) : solutions%.pdf : exercises%.tex instructions.tex
+	{ echo "\\documentclass[answers,12pt,a4paper,pdftex]{exam}"; sed -e '1d' $<; } > $(patsubst %.pdf,%.tex,$@)
+	pdflatex -interaction=scrollmode $(patsubst %.pdf,%.tex,$@) | tee /dev/stderr | fgrep -q "Rerun to get cross-references right" && pdflatex -interaction=scrollmode $(patsubst %.pdf,%.tex,$@) || true
+	rm $(patsubst %.pdf,%,$@).[!p]*
+
+$(EXERCISES) : %.pdf : %.tex instructions.tex
+	pdflatex -interaction=scrollmode $< | tee /dev/stderr | fgrep -q "Rerun to get cross-references right" && pdflatex -interaction=scrollmode $< || true
+
+watch :
+	while true; do ! make -q pdf && make pdf; sleep 0.5; done
+
+watchexercises :
+	while true; do ! make -q exercises && make exercises; sleep 0.5; done
+
+watchsolutions :
+	while true; do ! make -q solutions && make solutions; sleep 0.5; done
+
+clean :
+	rm -f *~ *.aux *.log *.out
+
+cleanup : clean
+	rm -f $(SOLUTIONS) $(EXERCISES)
diff --git a/bootstrap/exercises/UT_WBMW_Black_RGB.pdf b/bootstrap/exercises/UT_WBMW_Black_RGB.pdf
new file mode 100644
index 0000000..9aed921
Binary files /dev/null and b/bootstrap/exercises/UT_WBMW_Black_RGB.pdf differ
diff --git a/statistics/exercises/bootstrapmean.m b/bootstrap/exercises/bootstrapmean.m
similarity index 100%
rename from statistics/exercises/bootstrapmean.m
rename to bootstrap/exercises/bootstrapmean.m
diff --git a/statistics/exercises/bootstraptymus-datahist.pdf b/bootstrap/exercises/bootstraptymus-datahist.pdf
similarity index 100%
rename from statistics/exercises/bootstraptymus-datahist.pdf
rename to bootstrap/exercises/bootstraptymus-datahist.pdf
diff --git a/statistics/exercises/bootstraptymus-meanhist.pdf b/bootstrap/exercises/bootstraptymus-meanhist.pdf
similarity index 100%
rename from statistics/exercises/bootstraptymus-meanhist.pdf
rename to bootstrap/exercises/bootstraptymus-meanhist.pdf
diff --git a/statistics/exercises/bootstraptymus-samples.pdf b/bootstrap/exercises/bootstraptymus-samples.pdf
similarity index 100%
rename from statistics/exercises/bootstraptymus-samples.pdf
rename to bootstrap/exercises/bootstraptymus-samples.pdf
diff --git a/statistics/exercises/bootstraptymus.m b/bootstrap/exercises/bootstraptymus.m
similarity index 100%
rename from statistics/exercises/bootstraptymus.m
rename to bootstrap/exercises/bootstraptymus.m
diff --git a/statistics/exercises/correlationsignificance.m b/bootstrap/exercises/correlationsignificance.m
similarity index 100%
rename from statistics/exercises/correlationsignificance.m
rename to bootstrap/exercises/correlationsignificance.m
diff --git a/statistics/exercises/correlationsignificance.pdf b/bootstrap/exercises/correlationsignificance.pdf
similarity index 100%
rename from statistics/exercises/correlationsignificance.pdf
rename to bootstrap/exercises/correlationsignificance.pdf
diff --git a/statistics/exercises/statistics03.tex b/bootstrap/exercises/exercises01.tex
similarity index 100%
rename from statistics/exercises/statistics03.tex
rename to bootstrap/exercises/exercises01.tex
diff --git a/bootstrap/exercises/instructions.tex b/bootstrap/exercises/instructions.tex
new file mode 100644
index 0000000..12e9e24
--- /dev/null
+++ b/bootstrap/exercises/instructions.tex
@@ -0,0 +1,41 @@
+\vspace*{-6.5ex}
+\begin{center}
+\textbf{\Large Einf\"uhrung in die wissenschaftliche Datenverarbeitung}\\[1ex]
+{\large Jan Grewe, Jan Benda}\\[-3ex]
+Abteilung Neuroethologie \hfill --- \hfill Institut f\"ur Neurobiologie \hfill --- \hfill \includegraphics[width=0.28\textwidth]{UT_WBMW_Black_RGB} \\
+\end{center}
+
+\ifprintanswers%
+\else
+
+% Die folgenden Aufgaben dienen der Wiederholung, \"Ubung und
+% Selbstkontrolle und sollten eigenst\"andig bearbeitet und gel\"ost
+% werden. Die L\"osung soll in Form eines einzelnen Skriptes (m-files)
+% im ILIAS hochgeladen werden. Jede Aufgabe sollte in einer eigenen
+% ``Zelle'' gel\"ost sein. Die Zellen \textbf{m\"ussen} unabh\"angig
+% voneinander ausf\"uhrbar sein. Das Skript sollte nach dem Muster:
+% ``variablen\_datentypen\_\{nachname\}.m'' benannt werden
+% (z.B. variablen\_datentypen\_mueller.m).
+
+\begin{itemize}
+\item \"Uberzeuge dich von jeder einzelnen Zeile deines Codes, dass
+  sie auch wirklich das macht, was sie machen soll! Teste dies mit
+  kleinen Beispielen direkt in der Kommandozeile.
+\item Versuche die L\"osungen der Aufgaben m\"oglichst in
+  sinnvolle kleine Funktionen herunterzubrechen.
+  Sobald etwas \"ahnliches mehr als einmal berechnet werden soll,
+  lohnt es sich eine Funktion daraus zu schreiben!
+\item Teste rechenintensive \code{for} Schleifen, Vektoren, Matrizen
+  zuerst mit einer kleinen Anzahl von Wiederholungen oder kleiner
+  Gr\"o{\ss}e, und benutze erst am Ende, wenn alles \"uberpr\"uft
+  ist, eine gro{\ss}e Anzahl von Wiederholungen oder Elementen, um eine gute
+  Statistik zu bekommen.
+\item Benutze die Hilfsfunktion von \code{matlab} (\code{help
+    commando} oder \code{doc commando}) und das Internet, um
+  herauszufinden, wie bestimmte \code{matlab} Funktionen zu verwenden
+  sind und was f\"ur M\"oglichkeiten sie bieten.
+  Auch zu inhaltlichen Konzepten bietet das Internet oft viele
+  Antworten!
+\end{itemize}
+
+\fi
diff --git a/bootstrap/exercises/savefigpdf.m b/bootstrap/exercises/savefigpdf.m
new file mode 100644
index 0000000..fbe2dc2
--- /dev/null
+++ b/bootstrap/exercises/savefigpdf.m
@@ -0,0 +1,28 @@
+function savefigpdf( fig, name, width, height )
+% Saves figure fig in pdf file name.pdf with appropriately set page size
+% and fonts
+
+% default width:
+if nargin < 3
+    width = 11.7;
+end
+% default height:
+if nargin < 4
+    height = 9.0;
+end
+
+% paper:
+set( fig, 'PaperUnits', 'centimeters' );
+set( fig, 'PaperSize', [width height] );
+set( fig, 'PaperPosition', [0.0 0.0 width height] );
+set( fig, 'Color', 'white')
+
+% font:
+set( findall( fig, 'type', 'axes' ), 'FontSize', 12 )
+set( findall( fig, 'type', 'text' ), 'FontSize', 12 )
+
+% save:
+saveas( fig, name, 'pdf' )
+
+end
+
diff --git a/statistics/exercises/tdistribution-n03.pdf b/bootstrap/exercises/tdistribution-n03.pdf
similarity index 100%
rename from statistics/exercises/tdistribution-n03.pdf
rename to bootstrap/exercises/tdistribution-n03.pdf
diff --git a/statistics/exercises/tdistribution-n05.pdf b/bootstrap/exercises/tdistribution-n05.pdf
similarity index 100%
rename from statistics/exercises/tdistribution-n05.pdf
rename to bootstrap/exercises/tdistribution-n05.pdf
diff --git a/statistics/exercises/tdistribution-n10.pdf b/bootstrap/exercises/tdistribution-n10.pdf
similarity index 100%
rename from statistics/exercises/tdistribution-n10.pdf
rename to bootstrap/exercises/tdistribution-n10.pdf
diff --git a/statistics/exercises/tdistribution-n50.pdf b/bootstrap/exercises/tdistribution-n50.pdf
similarity index 100%
rename from statistics/exercises/tdistribution-n50.pdf
rename to bootstrap/exercises/tdistribution-n50.pdf
diff --git a/statistics/exercises/tdistribution.m b/bootstrap/exercises/tdistribution.m
similarity index 100%
rename from statistics/exercises/tdistribution.m
rename to bootstrap/exercises/tdistribution.m
diff --git a/statistics/exercises/thymusglandweights.dat b/bootstrap/exercises/thymusglandweights.dat
similarity index 100%
rename from statistics/exercises/thymusglandweights.dat
rename to bootstrap/exercises/thymusglandweights.dat
diff --git a/likelihood/exercises/Makefile b/likelihood/exercises/Makefile
new file mode 100644
index 0000000..27691d9
--- /dev/null
+++ b/likelihood/exercises/Makefile
@@ -0,0 +1,34 @@
+TEXFILES=$(wildcard exercises??.tex)
+EXERCISES=$(TEXFILES:.tex=.pdf)
+SOLUTIONS=$(EXERCISES:exercises%=solutions%)
+
+.PHONY: pdf exercises solutions watch watchexercises watchsolutions clean
+
+pdf : $(SOLUTIONS) $(EXERCISES)
+
+exercises : $(EXERCISES)
+
+solutions : $(SOLUTIONS)
+
+$(SOLUTIONS) : solutions%.pdf : exercises%.tex instructions.tex
+	{ echo "\\documentclass[answers,12pt,a4paper,pdftex]{exam}"; sed -e '1d' $<; } > $(patsubst %.pdf,%.tex,$@)
+	pdflatex -interaction=scrollmode $(patsubst %.pdf,%.tex,$@) | tee /dev/stderr | fgrep -q "Rerun to get cross-references right" && pdflatex -interaction=scrollmode $(patsubst %.pdf,%.tex,$@) || true
+	rm $(patsubst %.pdf,%,$@).[!p]*
+
+$(EXERCISES) : %.pdf : %.tex instructions.tex
+	pdflatex -interaction=scrollmode $< | tee /dev/stderr | fgrep -q "Rerun to get cross-references right" && pdflatex -interaction=scrollmode $< || true
+
+watch :
+	while true; do ! make -q pdf && make pdf; sleep 0.5; done
+
+watchexercises :
+	while true; do ! make -q exercises && make exercises; sleep 0.5; done
+
+watchsolutions :
+	while true; do ! make -q solutions && make solutions; sleep 0.5; done
+
+clean :
+	rm -f *~ *.aux *.log *.out
+
+cleanup : clean
+	rm -f $(SOLUTIONS) $(EXERCISES)
diff --git a/likelihood/exercises/UT_WBMW_Black_RGB.pdf b/likelihood/exercises/UT_WBMW_Black_RGB.pdf
new file mode 100644
index 0000000..9aed921
Binary files /dev/null and b/likelihood/exercises/UT_WBMW_Black_RGB.pdf differ
diff --git a/statistics/exercises/statistics04.tex b/likelihood/exercises/exercises01.tex
similarity index 100%
rename from statistics/exercises/statistics04.tex
rename to likelihood/exercises/exercises01.tex
diff --git a/likelihood/exercises/instructions.tex b/likelihood/exercises/instructions.tex
new file mode 100644
index 0000000..12e9e24
--- /dev/null
+++ b/likelihood/exercises/instructions.tex
@@ -0,0 +1,41 @@
+\vspace*{-6.5ex}
+\begin{center}
+\textbf{\Large Einf\"uhrung in die wissenschaftliche Datenverarbeitung}\\[1ex]
+{\large Jan Grewe, Jan Benda}\\[-3ex]
+Abteilung Neuroethologie \hfill --- \hfill Institut f\"ur Neurobiologie \hfill --- \hfill \includegraphics[width=0.28\textwidth]{UT_WBMW_Black_RGB} \\
+\end{center}
+
+\ifprintanswers%
+\else
+
+% Die folgenden Aufgaben dienen der Wiederholung, \"Ubung und
+% Selbstkontrolle und sollten eigenst\"andig bearbeitet und gel\"ost
+% werden. Die L\"osung soll in Form eines einzelnen Skriptes (m-files)
+% im ILIAS hochgeladen werden. Jede Aufgabe sollte in einer eigenen
+% ``Zelle'' gel\"ost sein. Die Zellen \textbf{m\"ussen} unabh\"angig
+% voneinander ausf\"uhrbar sein. Das Skript sollte nach dem Muster:
+% ``variablen\_datentypen\_\{nachname\}.m'' benannt werden
+% (z.B. variablen\_datentypen\_mueller.m).
+
+\begin{itemize}
+\item \"Uberzeuge dich von jeder einzelnen Zeile deines Codes, dass
+  sie auch wirklich das macht, was sie machen soll! Teste dies mit
+  kleinen Beispielen direkt in der Kommandozeile.
+\item Versuche die L\"osungen der Aufgaben m\"oglichst in
+  sinnvolle kleine Funktionen herunterzubrechen.
+  Sobald etwas \"ahnliches mehr als einmal berechnet werden soll,
+  lohnt es sich eine Funktion daraus zu schreiben!
+\item Teste rechenintensive \code{for} Schleifen, Vektoren, Matrizen
+  zuerst mit einer kleinen Anzahl von Wiederholungen oder kleiner
+  Gr\"o{\ss}e, und benutze erst am Ende, wenn alles \"uberpr\"uft
+  ist, eine gro{\ss}e Anzahl von Wiederholungen oder Elementen, um eine gute
+  Statistik zu bekommen.
+\item Benutze die Hilfsfunktion von \code{matlab} (\code{help
+    commando} oder \code{doc commando}) und das Internet, um
+  herauszufinden, wie bestimmte \code{matlab} Funktionen zu verwenden
+  sind und was f\"ur M\"oglichkeiten sie bieten.
+  Auch zu inhaltlichen Konzepten bietet das Internet oft viele
+  Antworten!
+\end{itemize}
+
+\fi
diff --git a/statistics/exercises/mlepdffit.m b/likelihood/exercises/mlepdffit.m
similarity index 100%
rename from statistics/exercises/mlepdffit.m
rename to likelihood/exercises/mlepdffit.m
diff --git a/statistics/exercises/mlepdffit.pdf b/likelihood/exercises/mlepdffit.pdf
similarity index 100%
rename from statistics/exercises/mlepdffit.pdf
rename to likelihood/exercises/mlepdffit.pdf
diff --git a/statistics/exercises/mlepropfit.m b/likelihood/exercises/mlepropfit.m
similarity index 100%
rename from statistics/exercises/mlepropfit.m
rename to likelihood/exercises/mlepropfit.m
diff --git a/statistics/exercises/mlepropfit.pdf b/likelihood/exercises/mlepropfit.pdf
similarity index 100%
rename from statistics/exercises/mlepropfit.pdf
rename to likelihood/exercises/mlepropfit.pdf
diff --git a/statistics/exercises/mleslope.m b/likelihood/exercises/mleslope.m
similarity index 100%
rename from statistics/exercises/mleslope.m
rename to likelihood/exercises/mleslope.m
diff --git a/statistics/exercises/mlestd.m b/likelihood/exercises/mlestd.m
similarity index 100%
rename from statistics/exercises/mlestd.m
rename to likelihood/exercises/mlestd.m
diff --git a/statistics/exercises/mlestd.pdf b/likelihood/exercises/mlestd.pdf
similarity index 100%
rename from statistics/exercises/mlestd.pdf
rename to likelihood/exercises/mlestd.pdf
diff --git a/likelihood/exercises/savefigpdf.m b/likelihood/exercises/savefigpdf.m
new file mode 100644
index 0000000..fbe2dc2
--- /dev/null
+++ b/likelihood/exercises/savefigpdf.m
@@ -0,0 +1,28 @@
+function savefigpdf( fig, name, width, height )
+% Saves figure fig in pdf file name.pdf with appropriately set page size
+% and fonts
+
+% default width:
+if nargin < 3
+    width = 11.7;
+end
+% default height:
+if nargin < 4
+    height = 9.0;
+end
+
+% paper:
+set( fig, 'PaperUnits', 'centimeters' );
+set( fig, 'PaperSize', [width height] );
+set( fig, 'PaperPosition', [0.0 0.0 width height] );
+set( fig, 'Color', 'white')
+
+% font:
+set( findall( fig, 'type', 'axes' ), 'FontSize', 12 )
+set( findall( fig, 'type', 'text' ), 'FontSize', 12 )
+
+% save:
+saveas( fig, name, 'pdf' )
+
+end
+
diff --git a/likelihood/lecture/likelihood-chapter.tex b/likelihood/lecture/likelihood-chapter.tex
index 2bcc35b..38d02d4 100644
--- a/likelihood/lecture/likelihood-chapter.tex
+++ b/likelihood/lecture/likelihood-chapter.tex
@@ -18,6 +18,11 @@
 
 \section{TODO}
 \begin{itemize}
+\item Fitting psychometric functions:
+  Variable $x_i$, responses $r_i$ either 0 or 1.
+  $p(x_i, \theta)$ is Weibull or Boltzmann function.
+  Likelihood is $L = \prod p(x_i, \theta)^{r_i} (1-p(x_i, \theta))^{1-r_i}$.
+  Use fminsearch for fitting.
 \item GLM model fitting?
 \end{itemize}
 
diff --git a/statistics/exercises/Makefile b/statistics/exercises/Makefile
index 925485d..27691d9 100644
--- a/statistics/exercises/Makefile
+++ b/statistics/exercises/Makefile
@@ -1,6 +1,6 @@
-TEXFILES=$(wildcard statistics??.tex)
+TEXFILES=$(wildcard exercises??.tex)
 EXERCISES=$(TEXFILES:.tex=.pdf)
-SOLUTIONS=$(EXERCISES:statistics%=solutions%)
+SOLUTIONS=$(EXERCISES:exercises%=solutions%)
 
 .PHONY: pdf exercises solutions watch watchexercises watchsolutions clean
 
@@ -10,7 +10,7 @@ exercises : $(EXERCISES)
 
 solutions : $(SOLUTIONS)
 
-$(SOLUTIONS) : solutions%.pdf : statistics%.tex instructions.tex
+$(SOLUTIONS) : solutions%.pdf : exercises%.tex instructions.tex
 	{ echo "\\documentclass[answers,12pt,a4paper,pdftex]{exam}"; sed -e '1d' $<; } > $(patsubst %.pdf,%.tex,$@)
 	pdflatex -interaction=scrollmode $(patsubst %.pdf,%.tex,$@) | tee /dev/stderr | fgrep -q "Rerun to get cross-references right" && pdflatex -interaction=scrollmode $(patsubst %.pdf,%.tex,$@) || true
 	rm $(patsubst %.pdf,%,$@).[!p]*
diff --git a/statistics/exercises/statistics01.tex b/statistics/exercises/exercises01.tex
similarity index 100%
rename from statistics/exercises/statistics01.tex
rename to statistics/exercises/exercises01.tex
diff --git a/statistics/exercises/statistics02.tex b/statistics/exercises/exercises02.tex
similarity index 100%
rename from statistics/exercises/statistics02.tex
rename to statistics/exercises/exercises02.tex