Interislander Ferry

Ranking Score Explained

G'day, thanks for your interest in how we calculate an experience's ranking score. It's at the core of Rankers so I'm pleased you're curious.

The ranking score percentage is used to compare and sort experiences in ranking tables. It is not necessarily a direct measurement of the quality of a particular experience as rated by its customers. I've found it a useful tool to allow me to find the best experiences with confidence. But I've also found it important to read the customer reviews before making any final judgements!

We calculate an experience's ranking score using a multi-factor data model instead of a raw data average (mean). This model takes into account several important questions. For instance - is there a trusted body of reviews? What is the age of a review and is the review from a credible source?

Below you'll find details around some of the important factors that went into calculating the ranking score for Interislander Ferry.

If you have any questions or comments about our ranking score calculation please get in touch at info@rankers.co.nz. We don't believe this is perfect or complete so we're always interested in ways we might make improvements.

Cymen Crick

Rankers Owner

Valid Reviews

350 Valid Reviews

The Interislander Ferry experience has a total of 361 reviews. There are 350 valid reviews that are included when calculating the ranking score and 11 invalid reviews that are excluded from the calculation. Reviews can be excluded only when a reviewer is not verified or after an investigation by our team determines the reviewer is not genuine.

Below is the distribution of ratings for the 350 valid reviews:

Rating	Count
10/10	41	12%
9/10	81	23%
8/10	103	29%
7/10	62	18%
6/10	29	8%
5/10	16	5%
4/10	7	2%
3/10	5	1%
2/10	2	1%
1/10	4	1%

77.20% Average

The raw data average (mean) for all the Interislander Ferry valid reviews is 77.20% and is based on 350 valid reviews. This value is not used to calculate the ranking score and it only provided here as a comparison to the weighted average.

Face-to-Face Reviews

309 Face-to-Face Reviews

The Rankers team meets with travellers while they’re in New Zealand and conducts face-to-face surveys. These reviews, in our opinion, are the most trusted in the industry and represent a critical control sample. To our knowledge, we are the only travel review website in the world that has gone to this extent.

More about face-to-face reviews

Within the 350 valid reviews, the experience has 309 face-to-face reviews collected during interviews by our team.

Below is the distribution of ratings for the 309 face-to-face reviews:

Rating	Count
10/10	30	10%
9/10	70	23%
8/10	98	32%
7/10	58	19%
6/10	25	8%
5/10	15	5%
4/10	6	2%
3/10	4	1%
2/10	2	1%
1/10	1	0%

77.22% Average

The raw data average (mean) for all the Interislander Ferry face-to-face reviews is 77.22% and is based on 309 face-to-face reviews. This value is not used to calculate the ranking score and it only provided here for comparison purposes.

Weighted Average

76.60%

Rankers calculates a weighted mean as a base average on which we can improve. Individual review's ratings are given a weight based on several factors. The weight of a review determines the overall impact it'll have on the final weighted average.

Recent reviews have more weight as they are more relevant and reflect the experience as it currently operates. Over time reviews become less relevant and loose their impact on the ranking score.

Low rating reviews carry slightly less weight. This dampens the effect of very low ratings for every experience across the board. This is especially important when the experience has few reviews overall and a single negative rating can grossly mischaracterise an experience. Consistent poor reviews will still result in the experience receiving a comparitively low ranking score.

Credible sources provide reviews that can be trusted. If we have verified a reviewer is genuine via a face-to-face meeting then the review carries additional weight.

Reviewer	Rating	Age	Relative Weight
Maria Longstaff	10/10	19 days	100%
Rina	9/10	141 days	98%
edm	1/10	415 days	37%
Colin Barrow	9/10	476 days	86%
Pauline	6/10	629 days	67%
Megan	5/10	781 days	50%
Marjolaine Loitz	4/10	811 days	41%
Keli Knox	10/10	1146 days	31%
Yar	1/10	1360 days	7%
Pinocity	6/10	1725 days	5%
Helen Russell	10/10	1906 days	5%
NewZealander	10/10	2180 days	4%
Tommy Pickett	9/10	3003 days	3%
Tom Bennett	8/10	3007 days	3%
Jeny Smolders	9/10	3009 days	3%
Gregg Wagstaff	7/10	3234 days	2%
Lianne Ijlst	8/10	3262 days	2%
Samantha and Neis	8/10	3263 days	2%
Brandon Cassidy	7/10	3279 days	2%
Vic Baughen	9/10	3281 days	2%
Anders Frank	7/10	3285 days	2%
Dina Schurer	8/10	3286 days	2%
Kim Youngsub	9/10	3287 days	2%
DEBBIE LAMBERT	10/10	3291 days	2%
Gary Williams	8/10	3291 days	2%
Kimberley Gardien	8/10	3298 days	2%
Antoine	9/10	3319 days	2%
Judit Van lanen	9/10	3324 days	2%
Bjorn Nielsen	8/10	3326 days	2%
Joel Virtanen	9/10	3328 days	2%
Corbin Hure	7/10	3328 days	2%
Ron	6/10	3331 days	2%
Thomas Simeon	8/10	3331 days	2%
Suzannah Hill	8/10	3332 days	2%
Kallan Mrozek	9/10	3333 days	2%
Kees Mol	9/10	3337 days	2%
Kristal Lavender	10/10	3337 days	2%
Bastian Bley	9/10	3338 days	2%
Jasmine Rogers	3/10	3339 days	1%
Louis Nilsson	8/10	3343 days	2%
Tim	7/10	3343 days	2%
Jendrik	6/10	3343 days	2%
Katharina	7/10	3344 days	2%
Chris Valchero	9/10	3347 days	2%
Rulp Niet	8/10	3349 days	2%
Soeren Buchheister	9/10	3350 days	2%
Chas Bronson	8/10	3350 days	2%
Jakob Lovdahl	9/10	3352 days	2%
Alexandra Schmidt	10/10	3362 days	2%
Jade Williams	10/10	3363 days	2%
Sam Staines	10/10	3364 days	2%
Nickolas Jonkergouw	7/10	3368 days	2%
Kirsty Smith	10/10	3368 days	2%
Eva Hesse	10/10	3383 days	2%
celine gries	8/10	3383 days	2%
tinagermany111	8/10	3398 days	2%
Cassandra Geyer	8/10	3582 days	2%
Olivier Reculeau	8/10	3583 days	2%
Thomas Michel	5/10	3584 days	1%
Lisa Haedrich	5/10	3588 days	1%
Nadja Guiliani	8/10	3592 days	2%
Elbrich	8/10	3592 days	2%
Jamie Serieux	7/10	3595 days	1%
Adele Jacques	9/10	3596 days	2%
Daniel Weber	6/10	3598 days	1%
Emily Noyd	8/10	3600 days	1%
Aparna Gula	10/10	3601 days	2%
Sebastiaan	7/10	3603 days	1%
Andre	9/10	3604 days	1%
Benedikt Hang	7/10	3605 days	1%
Yannick	8/10	3605 days	1%
S Black	9/10	3606 days	1%
Paul Larauze	6/10	3609 days	1%
Florence	6/10	3610 days	1%
Sarah Kovacs	8/10	3611 days	1%
Frenziska Schmid	7/10	3613 days	1%
Maud Livolsi	7/10	3620 days	1%
Lewis Whittle	6/10	3622 days	1%
Lukas Seager	6/10	3622 days	1%
Andrea Tabaka	8/10	3629 days	1%
Tina Rust	8/10	3631 days	1%
Joel Papak	8/10	3633 days	1%
Clemence and Pedro	9/10	3634 days	1%
Doms Wahlelr	9/10	3636 days	1%
Josef Biller	8/10	3636 days	1%
Justine Hoffmann	8/10	3637 days	1%
Friederike East	7/10	3637 days	1%
Mark White	10/10	3638 days	1%
Briony	8/10	3641 days	1%
Gabriel Siibers	8/10	3641 days	1%
Henry Wichler	8/10	3642 days	1%
Kyle Johnson	9/10	3644 days	1%
Niels Wezenberg	7/10	3645 days	1%
John Hamilton	9/10	3645 days	1%
Brianna Burd	9/10	3645 days	1%
Jessica Ruhland	8/10	3646 days	1%
Stula Vladimir	10/10	3647 days	1%
Cosmo Hartuna	7/10	3649 days	1%
Roland Fischer	6/10	3649 days	1%
Ross Holmes	9/10	3650 days	1%
Tilman	9/10	3652 days	1%
Petru	7/10	3653 days	1%
Fero Saarinen	6/10	3654 days	1%
Lauren Thompson	8/10	3656 days	1%
Meilin	8/10	3659 days	1%
Jonas Hoerning	10/10	3663 days	1%
Vanesha Patel	6/10	3664 days	1%
Mauricio Daniele	9/10	3664 days	1%
Sara and Antoine	8/10	3666 days	1%
Clare Pickford	6/10	3666 days	1%
Daniel Hill	10/10	3667 days	1%
Moritz Braun	7/10	3683 days	1%
Grischa Rodust	8/10	3690 days	1%
Chalie Dotesek	9/10	3691 days	1%
Julien Lafeville	7/10	3695 days	1%
Julia Huesam	8/10	3695 days	1%
Alexandre	9/10	3699 days	1%
Kev Zarka	6/10	3700 days	1%
Markus Wabing	8/10	3703 days	1%
Gessica	6/10	3736 days	1%
Simon Quass	9/10	3740 days	1%
Barthelemy	7/10	3969 days	1%
Brita Topp	10/10	4312 days	0%
Laim Thompson	8/10	4312 days	0%
Adriana	10/10	4320 days	0%
Pavel Jarolimek	5/10	4320 days	0%
Leonie Moeller	6/10	4321 days	0%
Doreen Gendel	8/10	4322 days	0%
Carla Oyarzun	3/10	4325 days	0%
Paolo Cases	3/10	4325 days	0%
Wolfgang and Christine	8/10	4330 days	0%
Helen	8/10	4343 days	0%
Olivier Carval	9/10	4345 days	0%
Hirsch Svenja	9/10	4346 days	0%
Mahr Svenja	8/10	4346 days	0%
Anna Guzewiez	9/10	4362 days	0%
Pier Durand	8/10	4366 days	0%
Serena Poggioli	9/10	4366 days	0%
Wayne Schist	7/10	4366 days	0%
Margreth Lydie	5/10	4374 days	0%
Laura Pleumeekers	7/10	4388 days	1%
David Brooks	10/10	4391 days	1%
Adrien Godeloup	9/10	4400 days	1%
Bet Dreno	8/10	4401 days	1%
Joachim	1/10	4402 days	0%
Pioter Jurkowski	7/10	4402 days	1%
Thomas Roche	9/10	4404 days	1%
Brian	9/10	4463 days	1%
hendrik king	9/10	4586 days	1%
Kiki Wykstra	5/10	4696 days	1%
Galen Licht	4/10	4696 days	1%
Yu-Ti Chu	7/10	4699 days	1%
Ton Martens	7/10	4699 days	1%
Joshua Perry	8/10	4704 days	1%
Molly Ladd	8/10	4704 days	1%
Michael Nolan	9/10	4708 days	1%
Julian Roots	9/10	4708 days	1%
Florent Corino	9/10	4712 days	1%
Amiot Cyriane	7/10	4712 days	1%
Annika	7/10	4712 days	1%
Jonas Herrmann	7/10	4712 days	1%
Matthieu Daveou	8/10	4712 days	1%
Julien Panossian	6/10	4712 days	1%
Raoul Montestruer	5/10	4712 days	1%
Alessa Ndra	8/10	4718 days	1%
Bjorn Hedmark	5/10	4719 days	1%
Evyatar Tulipman	7/10	4721 days	1%
S Curry	10/10	4736 days	1%
Ingrid	9/10	4780 days	1%
Reinier Timmer	7/10	4780 days	1%
Moorman	8/10	4789 days	1%
Stefan Roth	9/10	4814 days	1%
David	9/10	4828 days	1%
kevindang	10/10	4981 days	1%
Ruben Kunze	4/10	5063 days	1%
Sebastian Hol	9/10	5069 days	1%
Dick Stewart	8/10	5078 days	1%
David Beaumont	9/10	5085 days	1%
Beyeler	10/10	5090 days	1%
Nikita Sue	9/10	5095 days	1%
Schweiger	10/10	5097 days	1%
Jan & Marian	10/10	5176 days	1%
Konny	9/10	5180 days	1%
Waldemar Schuler	8/10	5180 days	1%
jule	3/10	5194 days	1%
Jack Potman	8/10	5396 days	1%
Jon_and_Family	9/10	5408 days	1%
Walker	9/10	5411 days	1%
Andreas Blessing	10/10	5419 days	1%
Gema	7/10	5422 days	1%
Avry Fabrice	6/10	5427 days	1%
Diane Johnston	9/10	5432 days	1%
Javier Munoz	8/10	5432 days	1%
Ben Akin-Smith	8/10	5433 days	1%
K Wallis	9/10	5438 days	1%
khs	9/10	5439 days	1%
Emma Ducat	9/10	5439 days	1%
Mr and Mrs Lambert	8/10	5446 days	1%
Andrew Koster	7/10	5452 days	1%
Bakker	8/10	5452 days	1%
Kimberly St Louis	8/10	5453 days	1%
Roel Wesstra	8/10	5459 days	1%
Seifert	10/10	5459 days	1%
Derek Woodward	9/10	5461 days	1%
Fabi & Sabi	8/10	5462 days	1%
Rosey834	8/10	5529 days	1%
Pete & Chris	10/10	5729 days	1%
Tony Masters	9/10	5792 days	1%
Hershell	8/10	5796 days	1%
Mike Robinson	9/10	5797 days	1%
Brent S	2/10	5798 days	0%
Zara Leyden	9/10	5806 days	1%
Judith	7/10	5810 days	1%
anon	8/10	5811 days	1%
Pierre Pilon	8/10	5812 days	1%
Jenny Omb	1/10	5817 days	0%
Frei Urs	6/10	5818 days	1%
Bryan Keddie	9/10	5828 days	1%
Leanne Rogan	5/10	5828 days	1%
Joanne Clarke	8/10	5832 days	1%
Wolfgang G	9/10	5838 days	1%
Thomas Signes	7/10	5859 days	1%
menzel	10/10	5877 days	1%
graemeh1	9/10	5878 days	1%
klinger	10/10	5878 days	1%
gereldineb	8/10	5888 days	1%
jennyb	9/10	5892 days	1%
Frank de Voogd	8/10	5898 days	1%
Jean Paul Mesnage	9/10	5904 days	1%
Hansjoerg Ehrmann	5/10	5905 days	1%
Daniel Alonso	9/10	5906 days	1%
Nigel Petrie	9/10	5917 days	1%
Tracy & Peter Cassidy	8/10	5933 days	1%
miniappleses	8/10	5955 days	1%
Josie Boyle	7/10	6066 days	1%
JanneP	9/10	6136 days	1%
Mikey	9/10	6143 days	1%
SablotniD	7/10	6148 days	1%
WiebkeS	9/10	6154 days	1%
Tanya	5/10	6156 days	1%
Jan	6/10	6156 days	1%
Viola	8/10	6157 days	1%
RowanL	7/10	6158 days	1%
VickiEngland	8/10	6166 days	1%
TomC1	8/10	6171 days	1%
AndyK	9/10	6171 days	1%
TatiamT	9/10	6171 days	1%
GillianK	8/10	6173 days	1%
EelcoK	9/10	6173 days	1%
Michael	9/10	6177 days	1%
soccaplaya14	10/10	6178 days	1%
Eugene	7/10	6180 days	1%
John	6/10	6182 days	1%
Tony	8/10	6187 days	1%
Middleton	4/10	6188 days	1%
Elise	8/10	6189 days	1%
Marie	8/10	6189 days	1%
ThomasS1	10/10	6193 days	1%
RasmusB	4/10	6195 days	1%
Simon	8/10	6200 days	1%
Phil&Joe	10/10	6203 days	1%
Marcus	7/10	6203 days	1%
Andre	7/10	6204 days	1%
Iris	9/10	6206 days	1%
Carla	7/10	6206 days	1%
Sandra	8/10	6211 days	1%
Schaffluber	10/10	6212 days	1%
Hayley	5/10	6212 days	1%
Con	2/10	6257 days	0%
felix	7/10	6258 days	1%
melissa	10/10	6264 days	1%
John B	5/10	6266 days	1%
Gemma	7/10	6305 days	1%
Henry	7/10	6306 days	1%
Antonella	10/10	6313 days	1%
Michelle	8/10	6313 days	1%
Laura	7/10	6322 days	1%
Sarah	8/10	6336 days	1%
Katerina	7/10	6357 days	1%
Erin	3/10	6357 days	1%
Mike Knight	9/10	6378 days	1%
Bronagh Mcartan	8/10	6387 days	1%
Dave	8/10	6398 days	1%
fgregory	10/10	6401 days	1%
Rhea	6/10	6446 days	1%
Georgina Mulligan	8/10	6458 days	1%
Karen C	7/10	6470 days	1%
Edmund Hillstone	10/10	6488 days	1%
Toby	6/10	6510 days	1%
Jennifer Baulch	9/10	6514 days	1%
Susan	8/10	6518 days	1%
Hoetnagels	7/10	6521 days	1%
Alan Bellerby	8/10	6524 days	1%
Sanne Jonker	7/10	6525 days	1%
Renske Tehurne	8/10	6529 days	1%
Benjamin Krein	7/10	6529 days	1%
Anne and Derek	8/10	6530 days	1%
James Davies	7/10	6530 days	1%
Naomi Horton	8/10	6531 days	1%
Roger Repolusk	8/10	6535 days	1%
Tony Wicks	6/10	6535 days	1%
Nancy Dol	8/10	6535 days	1%
Kristine	10/10	6535 days	1%
Kathy Hawey	9/10	6537 days	1%
David Buckley	8/10	6538 days	1%
Lena1	6/10	6539 days	1%
John Woodrow	8/10	6539 days	1%
Carmen Dolny	10/10	6539 days	1%
Haemnerli	8/10	6543 days	1%
Carla	8/10	6550 days	1%
Jim Curley	8/10	6550 days	1%
paulonline	7/10	6556 days	1%
Bex	6/10	6566 days	1%
Jenny Hulsebosch	8/10	6566 days	1%
Melissa Steedman	8/10	6577 days	1%
Tim	7/10	6578 days	1%
Falk Seidel	7/10	6581 days	1%
Hans Olthof	8/10	6581 days	1%
Anu	9/10	6584 days	1%
Anneli	6/10	6586 days	1%
purplekat99	10/10	6594 days	1%
Connor	10/10	6607 days	1%
Ad	7/10	6607 days	1%
Ann Westmacott	5/10	6612 days	1%
Paul Cowie	8/10	6613 days	1%
Ewen Maclean	8/10	6613 days	1%
Sarah Wilton	5/10	6613 days	1%
Arend v Dyn	7/10	6615 days	1%
Linda	8/10	6619 days	1%
Fiona	7/10	6619 days	1%
Ann	7/10	6620 days	1%
ranker_584	9/10	6623 days	1%
Christine	7/10	6623 days	1%
Nina	9/10	6623 days	1%
Anthony	7/10	6628 days	1%
Tom Clements	7/10	6628 days	1%
ranker_46	8/10	6740 days	1%
Pat Brewster	8/10	6740 days	1%
FrankOosterwijk	6/10	6825 days	1%
Kim	8/10	6825 days	1%
Helen	7/10	6856 days	1%
Heather	9/10	6856 days	1%
Helene	9/10	6868 days	1%
John	7/10	6868 days	1%
Giancarlo	6/10	6868 days	1%
Annette	4/10	6892 days	1%
John	5/10	6892 days	1%
Duncan	9/10	6897 days	1%
Jen	4/10	6908 days	1%
Rolf	8/10	6916 days	1%

Adjustments

Several adjustments to the weighted average are added to improve relevancy and credibility. These adjustments apply equally to all experiences that meet the criteria.

Sample Size Adjustment

No Adjustment

A reasonable number of reviews are necessary in order for the average to be credible and for an experience to take a prime position within the ranking tables. As such, experiences with only a few reviews have a moderated score. This does not mean that the experience or the reviews can't be trusted. The Interislander Ferry experience has plenty of reviews and does not meet the criteria for any adjustment.

Recent Reviews Adjustment

-0.29% Adjustment

There may be an adjustment if this experience hasn't received any reviews within the last 47 days. However the Interislander Ferry experience does not meet the criteria for any adjustment.

In addition, an experience's ranking score may be adjusted for each day there is no new ranking. After 1 day the adjustment comes into effect. The maximum number of days that can be adjusted for is 200 days. Due to the seasonal nature of many businesses, this adjustment is applied dynamically throughout the year.

The Interislander Ferry experience has been adjusted for 14 days. Adjustments are according to the following table.

Days	Adjustment
…	…
11	-0.23%
12	-0.25%
13	-0.27%
14	-0.29%
15	-0.31%
16	-0.33%
17	-0.35%
…	…

Balancing Adjustment

4.15% Adjustment

Every experience's review score is adjusted to balance out the disproportional number of negative reviews that are contributed.

You won't be surprised to learn that disgruntled customers are more likely to leave a review than happy ones. They are motivated to share their experience and warn others. We consider this a good thing and it's why reading the reviews is important. However we've learned it can misrepresent the experience in a more overall sense.

We apply a balancing adjustment to counteract this effect and ensure the ranking score is a more fair representation of the experience. This adjustment is applied equally to all experiences.

Final Ranking Score

81%

The final ranking score once any adjustments, ratings, and rounding has been applied. This value is recalculated each day and a short rolling average is applied. Therefore it may not be precisely accurate based on the other values presented.